### Engineering Mechanics Viva Questions

Engineering Mechanics Viva Questions
1.Look around in the lab and tell me how many Trusses do you see around.

A. I said the aluminum window panes.
2.Where is a flywheel most commonly used? and what is its primary use?
A. Its primarily used in a printing press, and its used mainly to store large amount of energy, in short bursts of time.
3.what is the difference between couple and moment
4.given the force in a diagram, find the moment.
5.explain coplanar forces
6.can coplanar forces be applied to any force system
7.define angle of restitution
8)what is reaction,or define reaction?
9)what is equilibrium?explain it with a rough diagram?
10)conditions of equilibrium?
11)what is pressure?
12)Explain
-angle of repose
-angle of friction
-what is force scale
-why is mu(s) greater than mu(k)
-laws of friction

13.What is restitution?
14.What is plastic collision?
15.What is elastic collision?
16.What is limiting friction?
17.What is the coefficient of restitution for a plastic collision?
18.When is the coefficient of restitution equal to 1?

### Java Practicals Viva Questions

Java Practicals Viva Questions
1)What is significance of import java.io.* in your program
2)difference between if and switch
3)difference between for and while loop
4)difference between do while and while loop
6)why is S capital in System.out.println
7)what are exceptions
8)types of exceptions
9)define data type
10)what is constant
11)what is meant by static
12)what are objects
13)what is a class
14)why do we have main() function
15)can two functions have same name
16)parts of for loop
17)examiner may ask you to tell what is control variable in your loop
18)difference between variable and constant
19)what are exceptions
20)what is use of throw

### Circuit and Systems Viva Questions

Circuit and Systems Viva Questions
1. What is a two port network..??
2. What are harmonics . And how and why does clipped sine wave forms.?
3. State millman 's theorem and give its limitations.
4. Tell something about Hurwitz Polynomials.
5. Define Fourier Theorem.
6. Differentiate between Fourier analysis and Fourier synthesis.
7. G-parameter - equation, equivalent circuit, circuit diagrams for experiment
8. Z-parameter - conditions for reciprocity and superposition
9. In given circuit, apply Superposition Theorem
10. What is a Transformer?
11. Uses of variac other than Lab
12. is 3 port n/w possible, if yes then how many variables in 3 port n/w ?
13. Unit of A,B,C,D.
14. Which theorem uses non linear n/w ?
15.disadvantages of z parameter
16.ideal voltage source
17.working of inductor & capacitor
18.what is inductor ?
19.is inductor & capacitor acts same ?
20.Which is most unstable in R,L & C ?
21.Damp, steady state, transient response

### CivilEngineering Viva Questions

CivilEngineering Viva Questions
1.What is a caisson?in which condition is this used?
2.what are the types of deep foundation?
3.what is open foundation?
4.what is the difference between designing & drafting?(in CAD lab)
5.what is procedure of design mix?

### Datastructures Viva Questions

Datastructures Viva Questions
Q1.What is a Register?
Ans- A register is a small amount of memory within the CPU that is used to temporarily store instructions and data.
Q2.An _________ data type is a keyword of a programming language that specifies the amount of memory needed to store data and the kind of data that will be stored in that memory location?
Ans-abstract
Q3.What are the different Abstract Data Type Groups?
A) Integer, Floating-Type, Character & Boolean are the four different data type groups
Explanation: You determine the amount of memory to reserve by determining the appropriate abstract data type group to use and then deciding which abstract data type within the group is right for the data. The different abstract data type groups are Integer, Floating-Type, Character & Boolean
Q4.Which of the following abstract data types are NOT used by Integer Abstract Data type group?
A) Short
B) Int
C) float
D) long
Explanation: The integer abstract data type group consists of four abstract data types used to reserve memory to store whole numbers: byte, short, int , and long
Q5.What pointer type is used to implement the heterogeneous linked list in C?
The answer is the void pointer. The heterogeneous linked list contains different data types in it's nodes and we need a link, pointer, to connect them. Since we can't use ordinary pointers for this, we use the void pointer. Void pointer is a generic pointer type, and capable of storing pointer to any type.
Q6.What is the minimum number of queues needed to implement the priority queue?
Two. One queue is used for the actual storing of data, and the other one is used for storing the priorities.
Q7.Which data structure is used to perform recursion?
The answer is Stack. Stack has the LIFO (Last In First Out) property; it remembers it's ‘caller’. Therefore, it knows to whom it should return when the function has to return. On the other hand, recursion makes use of the system stack for storing the return addresses of the function calls.
Every recursive function has its equivalent iterative (non-recursive) function. Even when such equivalent iterative procedures are written explicit, stack is to be used.
Q8.What are some of the applications for the tree data structure?
1- Manipulation of the arithmetic expressions.
2- Symbol table construction.
3- Syntax analysis.
Q9.Which data strucutres algorithm used in solving the eight Queens problem?
Backtracking
Q10.In an AVL tree, at what condition the balancing is to be done?
If the "pivotal value", or the "height factor", is greater than one or less than minus one.
Q11.There are 8, 15, 13, and 14 nodes in four different trees. Which one of them can form a full binary tree?
The answer is the tree with 15 nodes. In general, there are 2^n-1 nodes in a full binary tree.
By the method of elimination:
Full binary trees contain odd number of nodes, so there cannot be full binary trees with 8 or 14 nodes. Moreover, with 13 nodes you can form a complete binary tree but not a full binary tree. Thus, the correct answer is 15.

### c lab viva questions

c lab viva questions
1. C is ----------------type of language ?

Ans-Procedural.
2.Which are primitive datatypes in C?
Ans-int,Float,Char,Double,void ;
3.Memory size 0f int datatype?
Ans-2 bytes
4.Memory size of Character Datatype?
Ans-one bytes
5.Memory size of Float Datatype?
Ans-4 Bytes
6.What will be output of following code?
while(1)
{
printf("A");
}
Ans- Character A will be pritented on Screen until Heap memory is full. After that program terminates..
7.Difference b/w while and do...While?
Ans- While is Entry control loop.
Do While is Exit control Loop.

8.Which are user defined data types in C ?
Structure , Enumeration
9. What will following Statement indicates?
const int Key=10;
Ans- key is declared as Constant throughout the program key will have value 10
10.Difference b/w function declaration and function defenition?

Ans- Declaration means declaring a function.
eg- int sum(int,int);
It tell the compiler that we will use this function.
Defention means we are telling what the function will do..
eg- int sum(int a,int b)
{
int sum;
sum=a+b;
return(sum);
}

11.Syntax for function defenition?
returntype function name( datatype argument1,datatype argument1,.........argument n)
{
//statements
return( return value);
}

### Physics Viva Questions

1. Physics Viva Questions
2. State the Principle of a potentiometer. (The students say that potential drop is proportional to length but the constant quantities are not mentioned)
3. How can we increase the sensitivity of a potentiometer?
4. Define figure of merit of a galvanometer.
5. Which has more resistance – a galvanometer or a milliammeter?
6. How does an LED emit light?
7. What is the difference between an ordinary diode and an LED?
8. Define principal axis of a convex lens?
9. What happens to the focal length of a concave mirror if it is immersed in water?
10. What are the factors affecting the internal resistance of a cell?
11. What are the difference between primary and secondary cell?
12. Why can’t we use a dry cell for starting a car?
13. What happens to the resistivity of a wire when it is doublefolded?
14. How does the resistance of a wire depend on its dimensions?
15. Why are the resistances used in a resistance box is like 1,2,2,5,10,20,20,50,100,200,200,500,1000,2000,2000,5000 etc?
16. Why constantan or manganin wires are used for making the resistance coils in resistance box?
17. What is a standard resistance?
18. What are the characteristics of a standard resistance?
19. What are the precautions to be observed while doing electricity experiments in general?
20. What is a galvanometer?
21. What is the resistance of an ideal ammeter?
22. Why is ammeter always connected in series and voltmeter always connected in parallel?
23. How can we convert a galvanometer into an ammeter or a voltmeter?
24. What is shunt?
25. What is AVO meter?
26. What is the effect of temperature on the resistance of a conductor?
27. Why does the resistance of a conductor increases with temperature, whereas that of a semiconductor decreases with temperature.
28. What is conductance?
29. What are non ohmic devices? give an example.
30. What are superconductors?
31. Define emf
32. Why emf is said to be a misnomer?
33. What happens if the battery used in the primary circuit of a potentiometer has less emf compared to the emf of the cell used in the secondary circuit?
34. If you find that the galvanometer reading is shaky, what error can you expect?
35. What do you mean by figure of merit of a galvanometer?
36. Why a moving coil galvanometer is called so?
37. What is the principle of a galvanometer?

### Bs Lab Viva Questions

`Bs Lab Viva Questions1. Define Signal2. Define determistic and Random Signal3. Define Delta Function4. What is Signal Modeling5. Define Periodic and a periodic Signal6. Define Symetric and Anti-Symmetric Signals7. Define Continuous and Discrete Time Signals8. What are the Different types of representation of discrete time signals9. What are the Different types of Operation performed on signals10. What is System11. What is Causal Signal12. What are the Different types of Systems13. What is Linear System14. What is Time Invariant System15. What is Static and Dynamic System16. What is Even Signal17. What is Odd Signal18. Define the Properties of Impulse Signal19. What is Causality Condition of the Signal20. What is Condition for System Stability21. Define Convolution22. Define Properties of Convolution23. What is the Sufficient condition for the existence of F.T24. Define the F.T of a signal25. State Paeseval’s energy theorem for a periodic signal26. Define sampling Theorem27. What is Aliasing Effect28. what is Under sampling29. What is Over sampling30. Define Correlation31. Define Auto-Correlation32. Define Cross-Correlation33. Define Convolution34. Define Properties of Convolution35. What is the Difference Between Convolution& Correlation36. What are Dirchlet Condition37. Define Fourier Series38. What is Half Wave Symmetry39. What are the properties of Continuous-Time Fourier Series40. Define Laplace-Transform41. What is the Condition for Convergence of the L.T42. What is the Region of Convergence(ROC)43. State the Shifting property of L.T44. State convolution Property of L.T45. Define Transfer Function46. Define Pole-Zeros of the Transfer Function47. What is the Relationship between L.T & F.T &Z.T48. Fined the Z.T of a Impulse and step49. What are the Different Methods of evaluating inverse z-T50. Explain Time-Shifting property of a Z.T51. what are the ROC properties of a Z.T52. Define Initial Value Theorem of a Z.T53. Define Final Value Theorem of a Z.T54. Define Sampling Theorem55. Define Nyquist Rate56. Define Energy of a Signal57. Define Power of a signal58. Define Gibbs Phenomena59. Define the condition for distortionless transmission through the system60. What is signal band width61. What is system band width62. What is Paley-Winer criterion?63. Derive relationship between rise time and band width. `

### BEE Viva Questions Basic Electrical and Electronics Engineering

Basic Electrical and Electronics Engineering BEE Viva Questions
1. What are the types of transformers? Classify them construction-wise?
2. What is the voltage range of the regular ac supply v receive at home?
3. What is ripple factor? how will u eliminate d ac component?
4)what are the types of resistors?
5)what are the types of transistors?
6)definition of current, power, voltage, energy?
7)where is p-n-p transistor used and where is n-p-n transistor used?
8)can rectifiers work on AC or DC or both?
9)what are the types of motors?
10)why we have 240V, 50hz in india and 220V, 60hz in US?
11)what is mesh, what is loop
12)If we have full wave rectifier, then why do we use Bridge rectifier.
13)Trace the path of current in bridge rectifier.
14)What is the material used in LED. Symbol of LED.
15)What is a resistor?
16)What are types of network?
17)In polyphase, Star & Delta, why we use AC supply and not DC.
18)Define a Diode
19)What is Line and Phase Voltage?
20)Diode passes AC/DC ?
21)How to measure 20Vp-p on a CRO?
22)What is an open circuit transformer?
23)Explain the colour coding of resistors.
24)How to identify cathode and anode of a diode, if the silver band is absent?
25)What is charge?
26)What are the various types of Diodes and transistors?
27)At what voltage does a Computer work?
28)Diodes work on what AC or DC?
29)Can diodes work on dc too?-yes
30)What voltage is supplied to household appliances in india?-220v,50hz
31)If you are given 2 leds in series,then how will the resultant intensity of light be affected ?
32)First it will increase the resistance as it is connected in series,therefore the current will decrease and
33)intensity depends on current,thuse less current so less intensity.
and what happens in parellel ?-The intensity will remain same,as same voltage across each led
is equal and res. also the same so same current flows.
34)State superposition theorem.
35)I was given a circuit having two AC power sources connected to two seperate diodes individually and both these came together to connect to a common branch having a resistor. I was asked if it was possible to find out the current in the resistor by superposition.
A. yes, it will involve taking phasor addition of the currents due to the individual sources, which will be converted to half-rectified pulsating DC
36)I was given a particular RLC parallel circuit and told to derive resonance condition for THAT circuit.(consisted of three branches, one having only a resistor, other having a choke-coil and third having a capacitor in series with a resistor)
A. a totally messy form having no patter wt-so-ever.(the concerned look on the examiner's face made me believe my answer was right)
37) i was given a series AC circuit having two resistors and two inductors. i was told to derive resonance condition for that circuit.
A. do not stay under the assumption that it turns out to be L1=-L2....that is possible only if flux directions are opposite through the two coils, but since both were in the same circuit, in series, the flux will be the same through both. also since we can not have negative inductance as such, L1+L2=0 fails, thus the only possible condition is, that the inductances are purely resistive, or in short, the inductances are either not present, or negligible.
38)1)there are two types of transformers viz:-stup up and step down.....in step up transformer no of turns in secondary coil is more than in primary and in step down transformer the no of turns in secodary coil is less than that in primary coil.....
39)i think it is 230V,50Hz AC....
40)it is something linked with transistors.....presecnce of ac in dc is called ripple factor

### Vlsi lab Viva questions

Vlsi lab Viva questions
1) Tell something about why we do gate level simulations?
2) Say if I perform Formal Verification say Logical Equivalence across Gatelevel netlists(Synthesis and post routed netlist). Do you still see a reason behind GLS.?
3)An AND gate and OR gate are given inputs X & 1 , what is expected output?
4) What is difference between NMOS & RNMOS?
5) Tell something about modeling delays in verilog?
6) With a specify block how to defining pin-to-pin delays for the module ?
7) What are conditional path delays?
8) Tell something about Rise, fall, and turn-off delays?
9) What is delay modeling timing checks?
10)What are the synthesizable gate level constructs?
11) What are the synthesizable gate level constructs?
12) What are Design Rule Check (DRC)?
13) What is Layout Vs Schematic (LVS) ?
14) What are steps involved in Semiconductor device fabrication ?
15) What is Clock distribution network ?
16) What is Clock Gating ?
17) What is Netlist ?
18)What Physical timing closure ?
19)What Physical verification ?
20)What is Stuck-at fault ?
21)What is Different Logic family ?
22)What is Different Types of IC packaging?
23)What is Substrate coupling ?
24)What is Latchup ?
25)What is Body effect ?
26)What are standard Cell's?
27)Why is NAND gate preferred over NOR gate for fabrication?
28)What is Noise Margin? Explain the procedure to determine Noise Margin
29)Explain sizing of the inverter?
30)How do you size NMOS and PMOS transistors to increase the threshold voltage?
31)What happens to delay if you increase load capacitance?
32)What happens to delay if we include a resistance at the output of a CMOS circuit?
33)What are the limitations in increasing the power supply to reduce delay?
34)How does Resistance of the metal lines vary with increasing thickness and increasing length?
35)For CMOS logic, give the various techniques you know to minimize power consumption?
36)What is Charge Sharing? Explain the Charge Sharing problem while sampling data from a Bus?
37)Why do we gradually increase the size of inverters in buffer design? Why not give the output of a circuit to one large inverter?
38)How do you avoid Latch Up?
39)What is Body Effect?
40)Give the expression for CMOS switching power dissipation?
41)Why is the substrate in NMOS connected to Ground and in PMOS to VDD?
42)What is the fundamental difference between a MOSFET and BJT ?
43)Which transistor has higher gain. BJT or MOS and why?
44)Why do we gradually increase the size of inverters in buffer design when trying to drive a high capacitive load?
45)All of us know how an inverter works. What happens when the PMOS and NMOS are interchanged with one another in an inverter?
46)Why PMOS and NMOS are sized equally in a Transmission Gates?
47)A good question on Layouts. Give 5 important Design techniques you would follow when doing a Layout for Digital Circuits?
48)What is metastability? When/why it will occur?Different ways to avoid this?
49)Let A and B be two inputs of the NAND gate. Say signal A arrives at the NAND gate later than signal B. To optimize delay of the two series NMOS inputs A and B which one would you place near to the output?
50)Write a verilog code to swap contents of two registers with and without a temporary register?
51)Tell me about verilog file I/O?
52)Difference between task and function?
53)Difference between inter statement and intra statement delay?
54)What is delta simulation time?
55)Difference between \$monitor,\$display & \$strobe?
56)What is difference between Verilog full case and parallel case?
57)What is meant by inferring latches,how to avoid it?
58)Tell me how blocking and non blocking statements get executed?
59)Variable and signal which will be Updated first?
60)What is sensitivity list?
61)In a pure combinational circuit is it necessary to mention all the inputs in sensitivity disk? if yes, why?
62)Tell me structure of Verilog code you follow?
63)Given only two xor gates one must function as buffer and another as inverter?
64)What is difference between latch and flipflop?
65)Tell some of applications of buffer?
66)Give two ways of converting a two input NAND gate to an inverter?
67)What are set up time & hold time constraints?
68)Differences between D-Latch and D flip-flop?
69)What is a multiplexer?
70)How can you convert an SR Flip-flop to a JK Flip-flop?
71)How can you convert the JK Flip-flop to a D Flip-flop?
72)What is Race-around problem?How can you rectify it?
73)Difference between Synchronous,Asynchronous & Isynchronous communication?
74)In a 3-bit Johnson's counter what are the unused states?
75)What is difference between setup and hold time?
76)How will you implement a Full subtractor from a Full adder?
77)7 bit ring counter's initial state is 0100010. After how many clock cycles will it return to the initial state?
78)How do you detect if two 8-bit signals are same?
79)What is Race-around problem?How can you rectify it?
80)How can you convert the JK Flip-flop to a D Flip-flop?
81)How can you convert an SR Flip-flop to a JK Flip-flop?
82)What is a multiplexer?
83)Differences between D-Latch and D flip-flop?
84)Give two ways of converting a two input NAND gate to an inverter?
85)Tell some of applications of buffer?
86)What is difference between latch and flipflop?
87)Given only two xor gates one must function as buffer and another as inverter?
88)How can I pass parameters to my simulation?

### DigitalSystem Design Viva Questions

DigitalSystem Design Viva Questions
1)What are weighted and non weighted codes?
2)What is XS-3 Code?
3)What is Mux and DE-Mux?
4)What are different Types of gates we have?
5)Why Nand gate is called Universal gate?
6)Explain how you create 16:1 Mux using 4:1 Mux?
7)Basic System used in cell phone explain?
8)What is grey code used to make K-Maps?
9)Which is the best Minimization technique? Explain?
10)Explain about the experiment in detail to me?

### Electrical Engineering Lab Viva Questions

Electrical Engineering Lab Viva Questions
1. What is the need for starters?
2. Which is the basic protective device in any circuit?
3. Name the material used for Fuse.
4. Why is fuse rated for amperes?
5. What are the protective devices incorporated in DC starters?
6. Why is the field rheostat of dc motor kept at minimum resistance position and that of generator in maximum resistance position?
7. Why is the armature rheostat of dc motor kept at maximum resistance position?
8. Write the emf equation of DC and AC machine.
9. Write the torque equation of DC motor.
10. Draw the torque-slip characteristics of 3 phase induction motor and explain.
11.Explain the mechanical characteristics of DC shunt motor using electrical characteristics and N/Ia characteristics.
12. How are the ammeters and voltmeters connected in any circuit?
13. What is the difference between MI and MC type instruments?
14. How are MI meters used for measuring both ac and dc quantities?
15. Name the different types of DC and AC starters.
16. What is back emf? Give its significance.
17. What is the difference between self excited and separately excited machines?
18. Name the types of self excited dc machine.
19. Give the applications of each type of dc motor and dc generator.
20. What are the losses in dc machine?
21. How is the eddy current loss minimized in dc machine?
22. Name the parts of dc machine.
23. What is the use of commutator and brushes?
24. Name the material used for armature and core of dc machine.
25. Why is armature resistance less than field resistance of dc shunt machine?
26. Why is armature resistance more than field resistance of dc series machine?
27. Why is series motor best suited for traction applications?
28. Why shouldn’t dc series motor started at no load?
29. Define transformer.
30. What is the secondary side frequency of transformer?
31. What are the various types of transformer?
32. What are the methods of speed control of dc motors?
33. What do you mean by transformation coefficient?
34. What is the difference between two winding transformer and auto transformer?
35. Why transformers and alternators are rated with kVA?
36. What is the operating power factor of dc machine?
37. What is meant by power factor? Explain.
38. What do you mean by complex power?
39. What will happen if dc supply is connected to transformer?’
40. What are the parts of transformer?
41.What is regulation with respect to i)transformer ii)alternator
42. Why are synchronous motors not self starting? What are the methods of starting?
43. Why are single phase induction motors not self starting? Classify them according to the
starting methods.
44. What are the types of alternators?
45. Why is regulation so important for transformers and alternators?
46. What are the parts of synchronous machine? Name the material used in various parts.
47. Why is synchronous motor referred as doubly excited machine?
48. What is the result of varying the excitation of synchronous motor?
49. What is slip of an induction motor?
50. Why is always the induction motor running with less than the speed of rotating magnetic field?
51. What is slip frequency?
52. What will happen when the slip is 100% and zero?
53. What are the types of 3 phase induction motors?
54. How is the starting torque improved in slip ring induction motor? Justify mathematically.
55. Why is 3 phase induction motor referred as rotating transformer with short-circuited secondary?
56. What is the use of end rings in squirrel cage induction motor?
57. Why transformers have highest efficiency than any other electrical machine?
58. What is mutual inductance?
59.What is the principle of motor, generator and transformer?
60. How will you find the direction of induced emf in generator and the direction of motion of the conductor in motor?
61.How will you reverse the direction of rotation of i) dc motor ii) ac motor?
62. What is the difference between rheostat and potentiometer?
63. What is L, F, A, N in dc starters?
64. What is M, L, C, and V in wattmeter?
65. What is LPF, UPF and ZPF?
66. What is E and C in autotransformer?
67. What do you mean by power frequency?
68. What are the advantages and disadvantages of autotransformer?
69. What are the disadvantages of low power factor?
70. What are the methods of speed control of ac motors?
71.Why are electrical loads used for generators and motors whereas mechanical loads for motors?
72. What do you mean by stray losses in dc machine?
73. Given transformers A and B with following details:
A: Î·= 96% & reg: 5.8%
B: Î·= 94% & reg: 5.2%
Which transformer will you select? Justify your answer.
74.Given 4 terminals without indication. How will you manage to find the field and armature terminals of i) dc shunt machine ii) dc series machine.
75. What is the advantage of equivalent circuit?
76. What is meant by magnetizing current and working component of current with respect to transformer?
77. Give the relation between line and phase values of i) star connected network ii) delta connected network.
78.When can the squirrel cage machine be loaded to its fullest capacity? i) Star connection of stator ii) delta connection of stator.
79. How can the hysteresis loss of any machine be minimized?
80.What are the methods of electrical braking?
1. What is the need for starters?
2. Which is the basic protective device in any circuit?
3. Name the material used for Fuse.
4. Why is fuse rated for amperes?
5. What are the protective devices incorporated in DC starters?
6. Why is the field rheostat of dc motor kept at minimum resistance position and that of generator in maximum resistance position?
7. Why is the armature rheostat of dc motor kept at maximum resistance position?
8. Write the emf equation of DC and AC machine.
9. Write the torque equation of DC motor.
10. Draw the torque-slip characteristics of 3 phase induction motor and explain.
11.Explain the mechanical characteristics of DC shunt motor using electrical characteristics and N/Ia characteristics.
12. How are the ammeters and voltmeters connected in any circuit?
13. What is the difference between MI and MC type instruments?
14. How are MI meters used for measuring both ac and dc quantities?
15. Name the different types of DC and AC starters.
16. What is back emf? Give its significance.
17. What is the difference between self excited and separately excited machines?
18. Name the types of self excited dc machine.
19. Give the applications of each type of dc motor and dc generator.
20. What are the losses in dc machine?
21. How is the eddy current loss minimized in dc machine?
22. Name the parts of dc machine.
23. What is the use of commutator and brushes?
24. Name the material used for armature and core of dc machine.
25. Why is armature resistance less than field resistance of dc shunt machine?
26. Why is armature resistance more than field resistance of dc series machine?
27. Why is series motor best suited for traction applications?
28. Why shouldn’t dc series motor started at no load?
29. Define transformer.
30. What is the secondary side frequency of transformer?
31. What are the various types of transformer?
32. What are the methods of speed control of dc motors?
33. What do you mean by transformation coefficient?
34. What is the difference between two winding transformer and auto transformer?
35. Why transformers and alternators are rated with kVA?
36. What is the operating power factor of dc machine?
37. What is meant by power factor? Explain.
38. What do you mean by complex power?
39. What will happen if dc supply is connected to transformer?’
40. What are the parts of transformer?
41.What is regulation with respect to i)transformer ii)alternator
42. Why are synchronous motors not self starting? What are the methods of starting?
43. Why are single phase induction motors not self starting? Classify them according to the
starting methods.
44. What are the types of alternators?
45. Why is regulation so important for transformers and alternators?
46. What are the parts of synchronous machine? Name the material used in various parts.
47. Why is synchronous motor referred as doubly excited machine?
48. What is the result of varying the excitation of synchronous motor?
49. What is slip of an induction motor?
50. Why is always the induction motor running with less than the speed of rotating magnetic field?
51. What is slip frequency?
52. What will happen when the slip is 100% and zero?
53. What are the types of 3 phase induction motors?
54. How is the starting torque improved in slip ring induction motor? Justify mathematically.
55. Why is 3 phase induction motor referred as rotating transformer with short-circuited secondary?
56. What is the use of end rings in squirrel cage induction motor?
57. Why transformers have highest efficiency than any other electrical machine?
58. What is mutual inductance?
59.What is the principle of motor, generator and transformer?
60. How will you find the direction of induced emf in generator and the direction of motion of the conductor in motor?
61.How will you reverse the direction of rotation of i) dc motor ii) ac motor?
62. What is the difference between rheostat and potentiometer?
63. What is L, F, A, N in dc starters?
64. What is M, L, C, and V in wattmeter?
65. What is LPF, UPF and ZPF?
66. What is E and C in autotransformer?
67. What do you mean by power frequency?
68. What are the advantages and disadvantages of autotransformer?
69. What are the disadvantages of low power factor?
70. What are the methods of speed control of ac motors?
71.Why are electrical loads used for generators and motors whereas mechanical loads for motors?
72. What do you mean by stray losses in dc machine?
73. Given transformers A and B with following details:
A: Î·= 96% & reg: 5.8%
B: Î·= 94% & reg: 5.2%
Which transformer will you select? Justify your answer.
74.Given 4 terminals without indication. How will you manage to find the field and armature terminals of i) dc shunt machine ii) dc series machine.
75. What is the advantage of equivalent circuit?
76. What is meant by magnetizing current and working component of current with respect to transformer?
77. Give the relation between line and phase values of i) star connected network ii) delta connected network.
78.When can the squirrel cage machine be loaded to its fullest capacity? i) Star connection of stator ii) delta connection of stator.
79. How can the hysteresis loss of any machine be minimized?
80.What are the methods of electrical braking?
1. What is the need for starters?
2. Which is the basic protective device in any circuit?
3. Name the material used for Fuse.
4. Why is fuse rated for amperes?
5. What are the protective devices incorporated in DC starters?
6. Why is the field rheostat of dc motor kept at minimum resistance position and that of generator in maximum resistance position?
7. Why is the armature rheostat of dc motor kept at maximum resistance position?
8. Write the emf equation of DC and AC machine.
9. Write the torque equation of DC motor.
10. Draw the torque-slip characteristics of 3 phase induction motor and explain.
11.Explain the mechanical characteristics of DC shunt motor using electrical characteristics and N/Ia characteristics.
12. How are the ammeters and voltmeters connected in any circuit?
13. What is the difference between MI and MC type instruments?
14. How are MI meters used for measuring both ac and dc quantities?
15. Name the different types of DC and AC starters.
16. What is back emf? Give its significance.
17. What is the difference between self excited and separately excited machines?
18. Name the types of self excited dc machine.
19. Give the applications of each type of dc motor and dc generator.
20. What are the losses in dc machine?
21. How is the eddy current loss minimized in dc machine?
22. Name the parts of dc machine.
23. What is the use of commutator and brushes?
24. Name the material used for armature and core of dc machine.
25. Why is armature resistance less than field resistance of dc shunt machine?
26. Why is armature resistance more than field resistance of dc series machine?
27. Why is series motor best suited for traction applications?
28. Why shouldn’t dc series motor started at no load?
29. Define transformer.
30. What is the secondary side frequency of transformer?
31. What are the various types of transformer?
32. What are the methods of speed control of dc motors?
33. What do you mean by transformation coefficient?
34. What is the difference between two winding transformer and auto transformer?
35. Why transformers and alternators are rated with kVA?
36. What is the operating power factor of dc machine?
37. What is meant by power factor? Explain.
38. What do you mean by complex power?
39. What will happen if dc supply is connected to transformer?’
40. What are the parts of transformer?
41.What is regulation with respect to i)transformer ii)alternator
42. Why are synchronous motors not self starting? What are the methods of starting?
43. Why are single phase induction motors not self starting? Classify them according to the
starting methods.
44. What are the types of alternators?
45. Why is regulation so important for transformers and alternators?
46. What are the parts of synchronous machine? Name the material used in various parts.
47. Why is synchronous motor referred as doubly excited machine?
48. What is the result of varying the excitation of synchronous motor?
49. What is slip of an induction motor?
50. Why is always the induction motor running with less than the speed of rotating magnetic field?
51. What is slip frequency?
52. What will happen when the slip is 100% and zero?
53. What are the types of 3 phase induction motors?
54. How is the starting torque improved in slip ring induction motor? Justify mathematically.
55. Why is 3 phase induction motor referred as rotating transformer with short-circuited secondary?
56. What is the use of end rings in squirrel cage induction motor?
57. Why transformers have highest efficiency than any other electrical machine?
58. What is mutual inductance?
59.What is the principle of motor, generator and transformer?
60. How will you find the direction of induced emf in generator and the direction of motion of the conductor in motor?
61.How will you reverse the direction of rotation of i) dc motor ii) ac motor?
62. What is the difference between rheostat and potentiometer?
63. What is L, F, A, N in dc starters?
64. What is M, L, C, and V in wattmeter?
65. What is LPF, UPF and ZPF?
66. What is E and C in autotransformer?
67. What do you mean by power frequency?
68. What are the advantages and disadvantages of autotransformer?
69. What are the disadvantages of low power factor?
70. What are the methods of speed control of ac motors?
71.Why are electrical loads used for generators and motors whereas mechanical loads for motors?
72. What do you mean by stray losses in dc machine?
73. Given transformers A and B with following details:
A: Î·= 96% & reg: 5.8%
B: Î·= 94% & reg: 5.2%
Which transformer will you select? Justify your answer.
74.Given 4 terminals without indication. How will you manage to find the field and armature terminals of i) dc shunt machine ii) dc series machine.
75. What is the advantage of equivalent circuit?
76. What is meant by magnetizing current and working component of current with respect to transformer?
77. Give the relation between line and phase values of i) star connected network ii) delta connected network.
78.When can the squirrel cage machine be loaded to its fullest capacity? i) Star connection of stator ii) delta connection of stator.
79. How can the hysteresis loss of any machine be minimized?
80.What are the methods of electrical braking?

### Java Viva Questions Btech

Java Viva Questions Btech
1. Why java is Secured Compare with other Language?
2. What if the main method is declared as private?
3. What if the static modifier is removed from the signature of the main
method?
4. What if I write static public void instead of public static void?
5. What if I do not provide the String array as the argument to the
method?
6. What is the first argument of the String array in main method?
7. If I do not provide any arguments on the command line, then the
String array of Main method will be empty or null?
8. What environment variables do I need to set on my machine in order
to be able to run Java programs?
9. Can an application have multiple classes having main method?
10. In how many Ways we can create a Object in java?
11. Every Application Should ve a main() Method under which class does
the main() Method come Under?
12. What is Difference Between Static And Dynamic Polymarphism?
13. What happens If public Static void main() is made protected?
14. Can we Override the Main() Method?
15. What is the name of the java Complier used to compile the Source
File to byte code?
16. what is the use of static data member?
17. What does "wrapping" an object mean?
18. What is the difference between a while statement and a
do statement?
19. What is Constructor?
20. How are this() and super() used with constructors?
21. What is Difference between the Constructor and the Method?
22. What is the need of calling Default Constructor?
23. What is Difference between Instance and the Object?
24. What is System.Out.Println means?
25. What is JTI (Just in time) Engine means?
26. What is Differences Between Static & Final?
27. What is the difference between static and non-static
variables?
28. What is Differences Between class and Package?
29. What is String class?
30. What is Scanner Class in java?
31. What will a Static Variables is loaded ? Is at Compile time or Run
Time
32. What are the Primitive Types in java?
33. What is the difference between an Interface and an Abstract class?
34. What is the purpose of garbage collection in Java, and when is it
used?
35. What is the difference between a constructor and a method?
36. What is an Iterator?
37. State the significance of public, private, protected, default modifiers
both singly and in combination and state the effect of package
relationships on declared items qualified by these modifiers.
38. What is an abstract class?
39. What is static in java?
40. What is final ?
41. What are pass by reference and passby value?
42. Can I have multiple main methods in the same class?
43. How can one prove that the array is not null but empty using one line
of code?
44. Do I need to import java.lang package any time? Why ?
45. Can I import same package/class twice? Will the JVM load the
package twice at runtime?
46. What are Checked and UnChecked Exception?
47. What is Overriding?
48. What are different types of inner classes?
49. Does Java provide any construct to find out the size of an object?
50. What are wrapper classes?
51. Why do we need wrapper classes?
52. What are checked exceptions?
53. What are runtime exceptions?
54. What is the difference between error and an exception?? Question:
How to create custom exceptions?
55. If I want an object of my class to be thrown as an exception object,
what should I do?
56. If my class already extends from some other class what should I do if
I want an instance of my class to be thrown as an exception object?
57. How does an exception permeate through the code?
58. What are the different ways to handle exceptions?
59. What is the basic difference between the 2 approaches to exception
handling...1> try catch block and 2> specifying the candidate
exceptions in the throws clause hen should you use which approach?
60. Is it necessary that each try block must be followed by a catch block?
61. If I write return at the end of the try block, will the finally block still
execute?If I write System.exit (0); at the end of the try block, will the
finally block still execute?
62. Are the imports checked for validity at compile time? e.g. will the
code containing an import such as java.lang.ABCD compile?
63. Does importing a package imports the subpackages as well? e.g. Does
importing com.MyTest.* also import com.MyTest.UnitTests.*?
64. What is the difference between declaring a variable and defining a
variable?
65. What is the default value of an object reference declared as an
instance variable?
66. Can a top level class be private or protected?
67. What type of parameter passing does Java support?
68. Primitive data types are passed by reference or pass by value?
69. Objects are passed by value or by reference?
70. What is serialization?
71. How do I serialize an object to a file?
72. What happens to the static fields of a class during serialization?
73. Describe synchronization in respect to multithreading.
74. Explain different way of using thread?
75. What is HashMap and Map?
76. Difference between HashMap and HashTable?
77. Difference between Vector and ArrayList?
78. Difference between Swing and Awt?
79. What is synchronization and why is it important?
80. Does garbage collection guarantee that a program will
not run out of
memory?
81. How does Java handle integer overflows and
underflows?
82. What is the difference between preemptive scheduling
and time slicing?
83. When a thread is created and started, what is its initial
state?
84. What is the purpose of finalization?
85. What is the Locale class?
86. What are synchronized methods and synchronized
statements?
87. What is daemon thread and which method is used to create the
88. Can applets communicate with each other?

### OperatingSystem Lab Viva Questions

OPERATING SYSTEM VIVA QUESTIONS

1. Explain the concept of Reentrancy?

It is a useful, memory-saving technique for multiprogrammed timesharing systems. A Reentrant Procedure is one in which multiple users can share a single copy of a program during the same period. Reentrancy has 2 key aspects: The program code cannot modify itself, and the local data for each user process must be stored separately. Thus, the permanent part is the code, and the temporary part is the pointer back to the calling program and local variables used by that program. Each execution instance is called activation. It executes the code in the permanent part, but has its own copy of local variables/parameters. The temporary part associated with each activation is the activation record. Generally, the activation record is kept on the stack.
Note: A reentrant procedure can be interrupted and called by an interrupting program, and still execute correctly on returning to the procedure.

2. Explain Belady's Anomaly?

Also called FIFO anomaly. Usually, on increasing the number of frames allocated to a process virtual memory, the process execution is faster, because fewer page faults occur. Sometimes, the reverse happens, i.e., the execution time increases even when more frames are allocated to the process. This is Belady's Anomaly. This is true for certain page reference patterns.

3. What is a binary semaphore? What is its use?

A binary semaphore is one, which takes only 0 and 1 as values. They are used to implement mutual exclusion and synchronize concurrent processes.

4. What is thrashing?

It is a phenomenon in virtual memory schemes when the processor spends most of its time swapping pages, rather than executing instructions. This is due to an inordinate number of page faults.

5. List the Coffman's conditions that lead to a deadlock.

1. Mutual Exclusion: Only one process may use a critical resource at a time.

2. Hold & Wait: A process may be allocated some resources while waiting for others.

3. No Pre-emption: No resource can be forcible removed from a process holding it.

4. Circular Wait: A closed chain of processes exist such that each process holds at least one resource needed by another process in the chain.

6. What are short, long and medium-term scheduling?

Long term scheduler determines which programs are admitted to the system for processing. It controls the degree of multiprogramming. Once admitted, a job becomes a process.

Medium term scheduling is part of the swapping function. This relates to processes that are in a blocked or suspended state. They are swapped out of real-memory until they are ready to execute. The swapping-in decision is based on memory-management criteria.

Short term scheduler, also know as a dispatcher executes most frequently, and makes the finest-grained decision of which process should execute next. This scheduler is invoked whenever an event occurs. It may lead to interruption of one process by preemption.

7. What are turnaround time and response time?

Turnaround time is the interval between the submission of a job and its completion. Response time is the interval between submission of a request, and the first response to that request.

8. What are the typical elements of a process image?

User data: Modifiable part of user space. May include program data, user stack area, and programs that may be modified.

User program: The instructions to be executed.

System Stack: Each process has one or more LIFO stacks associated with it. Used to store parameters and calling addresses for procedure and system calls.

Process control Block (PCB): Info needed by the OS to control processes.

9. What is the Translation Lookaside Buffer (TLB)?

In a cached system, the base addresses of the last few referenced pages is maintained in registers called the TLB that aids in faster lookup. TLB contains those page-table entries that have been most recently used. Normally, each virtual memory reference causes 2 physical memory accesses- one to fetch appropriate page-table entry, and one to fetch the desired data. Using TLB in-between, this is reduced to just one physical memory access in cases of TLB-hit.

10. What is the resident set and working set of a process?

Resident set is that portion of the process image that is actually in real-memory at a particular instant. Working set is that subset of resident set that is actually needed for execution. (Relate this to the variable-window size method for swapping techniques.)

11. When is a system in safe state?

The set of dispatchable processes is in a safe state if there exists at least one temporal order in which all processes can be run to completion without resulting in a deadlock.

12. What is cycle stealing?

We encounter cycle stealing in the context of Direct Memory Access (DMA). Either the DMA controller can use the data bus when the CPU does not need it, or it may force the CPU to temporarily suspend operation. The latter technique is called cycle stealing. Note that cycle stealing can be done only at specific break points in an instruction cycle.

13. What is meant by arm-stickiness?

If one or a few processes have a high access rate to data on one track of a storage disk, then they may monopolize the device by repeated requests to that track. This generally happens with most common device scheduling algorithms (LIFO, SSTF, C-SCAN, etc). High-density multisurface disks are more likely to be affected by this than low density ones.

14. What are the stipulations of C2 level security?

C2 level security provides for:

1. Discretionary Access Control

2. Identification and Authentication

3. Auditing

4. Resource reuse

15. What is busy waiting?

The repeated execution of a loop of code while waiting for an event to occur is called busy-waiting. The CPU is not engaged in any real productive activity during this period, and the process does not progress toward completion.

16. Explain the popular multiprocessor thread-scheduling strategies.

1. Load Sharing: Processes are not assigned to a particular processor. A global queue of threads is maintained. Each processor, when idle, selects a thread from this queue. Note that load balancing refers to a scheme where work is allocated to processors on a more permanent basis.

2. Gang Scheduling: A set of related threads is scheduled to run on a set of processors at the same time, on a 1-to-1 basis. Closely related threads / processes may be scheduled this way to reduce synchronization blocking, and minimize process switching. Group scheduling predated this strategy.

3. Dedicated processor assignment: Provides implicit scheduling defined by assignment of threads to processors. For the duration of program execution, each program is allocated a set of processors equal in number to the number of threads in the program. Processors are chosen from the available pool.

4. Dynamic scheduling: The number of thread in a program can be altered during the course of execution.

17. When does the condition 'rendezvous' arise?

In message passing, it is the condition in which, both, the sender and receiver are blocked until the message is delivered.

18. What is a trap and trapdoor?

Trapdoor is a secret undocumented entry point into a program used to grant access without normal methods of access authentication. A trap is a software interrupt, usually the result of an error condition.

19. What are local and global page replacements?

Local replacement means that an incoming page is brought in only to the relevant process address space. Global replacement policy allows any page frame from any process to be replaced. The latter is applicable to variable partitions model only.

20. Define latency, transfer and seek time with respect to disk I/O.

Seek time is the time required to move the disk arm to the required track. Rotational delay or latency is the time it takes for the beginning of the required sector to reach the head. Sum of seek time (if any) and latency is the access time. Time taken to actually transfer a span of data is transfer time.

21. Describe the Buddy system of memory allocation.

Free memory is maintained in linked lists, each of equal sized blocks. Any such block is of size 2^k. When some memory is required by a process, the block size of next higher order is chosen, and broken into two. Note that the two such pieces differ in address only in their kth bit. Such pieces are called buddies. When any used block is freed, the OS checks to see if its buddy is also free. If so, it is rejoined, and put into the original free-block linked-list.

22. What is time-stamping?

It is a technique proposed by Lamport, used to order events in a distributed system without the use of clocks. This scheme is intended to order events consisting of the transmission of messages. Each system 'i' in the network maintains a counter Ci. Every time a system transmits a message, it increments its counter by 1 and attaches the time-stamp Ti to the message. When a message is received, the receiving system 'j' sets its counter Cj to 1 more than the maximum of its current value and the incoming time-stamp Ti. At each site, the ordering of messages is determined by the following rules: For messages x from site i and y from site j, x precedes y if one of the following conditions holds....(a) if Ti

23. How are the wait/signal operations for monitor different from those for semaphores?

If a process in a monitor signal and no task is waiting on the condition variable, the signal is lost. So this allows easier program design. Whereas in semaphores, every operation affects the value of the semaphore, so the wait and signal operations should be perfectly balanced in the program.

24. In the context of memory management, what are placement and replacement algorithms?

Placement algorithms determine where in available real-memory to load a program. Common methods are first-fit, next-fit, best-fit. Replacement algorithms are used when memory is full, and one process (or part of a process) needs to be swapped out to accommodate a new program. The replacement algorithm determines which are the partitions to be swapped out.

25. In loading programs into memory, what is the difference between load-time dynamic linking and run-time dynamic linking?

For load-time dynamic linking: Load module to be loaded is read into memory. Any reference to a target external module causes that module to be loaded and the references are updated to a relative address from the start base address of the application module.

With run-time dynamic loading: Some of the linking is postponed until actual reference during execution. Then the correct module is loaded and linked.

26. What are demand-paging and pre-paging?

With demand paging, a page is brought into memory only when a location on that page is actually referenced during execution. With pre-paging, pages other than the one demanded by a page fault are brought in. The selection of such pages is done based on common access patterns, especially for secondary memory devices.

27. Paging a memory management function, while multiprogramming a processor management function, are the two interdependent?

Yes.

28. What is page cannibalizing?

Page swapping or page replacements are called page cannibalizing.

29. What has triggered the need for multitasking in PCs?

1. Increased speed and memory capacity of microprocessors together with the support fir virtual memory and

2. Growth of client server computing

30. What are the four layers that Windows NT have in order to achieve independence?

1. Hardware abstraction layer

2. Kernel

3. Subsystems

4. System Services.

31. What is SMP?

To achieve maximum efficiency and reliability a mode of operation known as symmetric multiprocessing is used. In essence, with SMP any process or threads can be assigned to any processor.

32. What are the key object oriented concepts used by Windows NT?

Encapsulation, Object class and instance.

33. Is Windows NT a full blown object oriented operating system? Give reasons.

No Windows NT is not so, because its not implemented in object oriented language and the data structures reside within one executive component and are not represented as objects and it does not support object oriented capabilities.

34. What is a drawback of MVT?

It does not have the features like

1. ability to support multiple processors

2. virtual storage

3. source level debugging

35. What is process spawning?

When the OS at the explicit request of another process creates a process, this action is called process spawning.

36. How many jobs can be run concurrently on MVT?

15 jobs.

37. List out some reasons for process termination.

1. Normal completion

2. Time limit exceeded

3. Memory unavailable

4. Bounds violation

5. Protection error

6. Arithmetic error

7. Time overrun

8. I/O failure

9. Invalid instruction

10. Privileged instruction

11. Data misuse

12. Operator or OS intervention

13. Parent termination.

38. What are the reasons for process suspension?

1. swapping

2. interactive user request

3. timing

4. parent process request

39. What is process migration?

It is the transfer of sufficient amount of the state of process from one machine to the target machine.

40. What is mutant?

In Windows NT a mutant provides kernel mode or user mode mutual exclusion with the notion of ownership.

41. What is an idle thread?

The special thread a dispatcher will execute when no ready thread is found.

42. What is FtDisk?

It is a fault tolerance disk driver for Windows NT.

43. What are the possible threads a thread can have?

2. Standby

3. Running

4. Waiting

5. Transition

6. Terminated

44. What are rings in Windows NT?

Windows NT uses protection mechanism called rings provides by the process to implement separation between the user mode and kernel mode.

45. What is Executive in Windows NT?

In Windows NT, executive refers to the operating system code that runs in kernel mode.

46. What are the sub-components of I/O manager in Windows NT?

1. Network redirector/ Server

2. Cache manager.

3. File systems

4. Network driver

5. Device driver

47. What are DDks? Name an operating system that includes this feature.

DDks are device driver kits, which are equivalent to SDKs for writing device drivers. Windows NT includes DDks.

48. What level of security does Windows NT meets?

C2 level security.