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1. which of the following statements is correct?


the current in a short circuit is always zero


the current in an open circuit is always zero


the resistance in an open circuit is always zero


None of the above


2. which of the following statements is correct?


the voltage in a short circuit is always zero


the voltage in an open circuit is always zero


the resistance in an open circuit is always infinity


None of the above


3. Several light bulbs are connected in parallel and one light bulb burns out,the other light bulbs:

All bulbs stop working


All bulbs light more


All bulbs burn out


none of the above


4. Several light bulbs are connected in series and one light bulb burns out, the other light bulbs:


All bulbs stop working


All bulbs light more


All bulbs burn out


None of the above


5. Fuses are used to


(A)Protect the circuit I equipment


(B)Keep wires overheated from getting


(C)Break the circuit when too much current is being used

All of the above


6. An electric kettle is rated at 1000W for use in a 220-V circuit. A 12A circuit fuse I breaker is installed on 1 the circuit. How many kettles can be safely operated in the circuit?

More than 4


3


2


1


7. Electrical devices in our homes are connected in


Parallel


Series


Both series and parallel


None of the above


8. If you plug an electric toaster rated at 110V into a 220-V outlet, current in the toaster will be


The same as if it were plugged into 110V


Twice what it should be


Half what it should be


None of the above


9. When a current flows through a resistance for time the electrical energy spent is given by


IR·t


I2R·t


IR2·t


I2R/t


10. Kilowatt-hour is the unit of:


Potential difference


Electric power


Electrical energy


Electric charge


11. The power dissipated in a resistor is directly proportional to


The current through this resistor


The resistor value


The voltage across the resistance


All of the above


12. Transformer action requires:


Alternating electric flux


Alternating magnetic flux


Constant magnetic flux


Any of the above


13. A commutator in a dc generator provides:


Half-wave rectification


Full-wave rectification


Half-wave controlled rectification


FUll-wave controlled rectification


14. In a three-phase induction motor, the maximum torque is


Independent of rotor resistance


Proportional to rotor resistance


Proportional to square of rotor resistance


Proportional to square root of rotor resistance


15. Rated speed of a three-phase induction motor is 1,440 rpm for 50 Hz supply, the number of pole is

6-pole


2-pole


8-pole


4-pole


16. If the roter of induction motor rotates at synchronous speed, the torque produced is


(A)High


(B)Low


(C)Zero


(D)Infinity


17. In 50 Hz induction machine, if the no load speed is 745 rpm, the synchronous speed is

(A)700 rpm


(B)750 rpm


(C)800 rpm


(D)850 rpm


18. In 50Hz induction machine, if the no load speed is 2900 rpm, the slip frequency is


0.33 Hz


0.67 Hz


1.33 Hz


1.67 Hz


19. If P number of poles and N revolution made per second, what is the frequency of an alternator


PN/2 Hz


120/PN Hz


120 N/P Hz


120 P/N Hz


20. A series motor is efficiently suitable for:


High starting torque operation


Low starting torque operation


Constant speed operation


None of the above


21. Refer to the circuit of figure below, if Vx VR 9V, then the power absorbed by element R is

<img src='./qimages/4189-21.jpg'>

5W


9W


40W


45W

22. A certain practical dc voltage source can provide a current of 2.5A when it is short-circuited and can provide a power of 80 W to a 20 ohm load. The open circuit voltage of the source is


22.2V


80V


8.88V


200V


23. The current through a capacitor is given by 7 sin(piet)mA. If the energy stored at t 200 ms is 3mewJ, what is the value of the capacitance?


2.99 mF


3.02 mewF


18.14nF


7.00mF


24. The value of voltage Vx in the following circuit is


<img src='./qimages/4189-24.jpg'>


9.89 cos(400t 78.76°) V


7.80 cos(400t 48.9°) V


5.00 cos(400t V


1.95 cos(400t -41.21°) V


25. The power delivered in VA to a load that draws 500 W at a leading power factor of 0.75 is:


500 -41.41°


500 41.41°


666.7 -41.41°


666.7 +41.41°


26. For a particular circuit, it is known that V12 V=60 V 45 120° and V35 all in volts. Then V25 in volts will equal to


(A)189.8 34.95°


(B)56.67 -11.520V


130°


(D)43.48


27. A parallel RLC circuit is measured to have a quality factor of 200 at resonant frequency. The value of if R=1k ohm and C mewF is


25mewH


25mewH


40mH


40nH


28. A signal 10e-2t is applied to a linear system for which the impulse response is =10e-2t The output is


100e-2t


=100te-2t


10e-2t


1ote-2t


29. If and then will be equal to





20(e-2t


20(e-3t e­2t)






30. In the circuit shown below, the current through the inductor is

<img src='./qimages/4189-30.jpg'>


A


A


A


0A


31. For the circuit shown in the figure, the voltage and current expressions are E1 sin(wt) E3 sin(3wt) and I1 sin (wt pie I3 sin (3wt pie3) I5 sin(5wt). The average power measured by the wattmeter is


<img src='./qimages/4189-31.jpg'>


32. In the following figure, C1 and C2 are ideal capacitors. C1 has been charged to 12 V before the ideal switch S is closed at t O. The current for all t is

<img src='./qimages/4189-32.jpg'>


(A)Zero


step function


exponentially decaying function


impulse function


33. With sources iA and vB in the following circuit arid vc ix=20A,with iA and VC o nand vB= ix A and finally, with all three sources on, ix 12 the value of i x if only iA is operating is:

<img src='./qimages/4189-33.jpg'>








(C)17A





34. A circuit consists of a 0.5H inductor, a 10ohm resistor and a 40ohm resistor in series. The inductor current is 4 A at t 0. The inductor current after 15 ms becomes:


(A)0.89A


(B)0.68A


(C)0.57A


(D)0.45A


35. A practical current source provides 10W to a 250ohm load and 20 W to an 80 ohm load. A resistance RL with voltage vL and current iL, is connected to it. If iL is a maximum, then the value of RL is


(A)33.33 ohm


(B)Infinite


(C)Zero


(D)60.61 ohm


36. The voltage across a 5H inductor is =10 If 80 mA, the final value of inductor current is:


(A)0.08A


(B)1.08A


(C)0.47A


(D)Zero


37. A current source of 4A, a 20ohm resistor and a 5mewF capacitor are all in parallel. The amplitude of the current source drops suddenly to zero at t 0. The time at which the capacitor voltage drops to one-half of its initial value is


(A)34.66mews


(B)69.3mews


(C)0.69mewsS


(D)507.5mews


38. If the admittance of the parallel combination of a 10ohm resistance and a 50mewF capacitance at w 1 krad/s is the same as the admittance of R1 and C1 in the series at that frequency, then the value of C1 is


(A)250mewF


(B)0.05mewF


(C)100mewF


(D)8mewF


39. The value of RL in the following circuit L that will absorb a maximum power is:

<img src='./qimages/4189-39.jpg'>


(A)4ohm


(B)8ohm


(C)12ohm


(D)8.9ohm


40. <img src='./qimages/4189-40.jpg'>


41. A system has an overall transfer function equal to a2/S2 where a is a positive constant. For large values of time the output approximately resembles:


Ramp function


A unit step function


An exponential function


A quadratic function


42. The output of a linear time invariant control system is for a certain input If is modified by passing it through a block whose transfer function is e-s and then applied to the system, the modified output of the system would be:















43. <img src='./qimages/4189-43.jpg'>


The signal flow graph for the above system is:

<img src='./qimages/4189-43-1.jpg'>



44. If for a closed loop control system having open loop gain and feedback path gain the position error constant Kp 1 and p acceleration error constant Ka 0.5 then the steady state error for input is





5


8





45. A system has overall closed loop gain 36/S2+9S+36.If a step input is given to the system, what is the time duration between first two successive peak overshoots?


1.58


2pie/3


0.81


1.8


46. A system has overall transfer function The eXpression for peak time tP can be obtained by equating to zero, the derivative of:


(A)Input with respect to time


(B)The convolution of r(t)and with respect to time


with respect to time where is the system response


delta(t)T(p) with respect to time, where delta(t) is the impulse response


47. If state equation is 3
0 X
and
2]. The states for
any time t>0 are:

<img src='./qimages/4189-47.jpg'>


48. <img src='./qimages/4189-48.jpg'>

The transfer function of the above bode plot may be

<img src='./qimages/4189-48-1.jpg'>


49. The Asymptote in the Bode Plot for

<img src='./qimages/4189-49.jpg'>


50. When a lag compensator is used for the compensation of a system, the magnitude bode plot of the compensated system:


(A)Remains unaltered


(B)Always lies below the uncompensated system


(C)Always lies above the uncompensated system


(D)Remains unaltered upto some low frequency and lies below the uncompensated system for higher frequencies.


51. causes offset error and
can be used to remove it.


Integral controller, proportional controller


Proportional controller, integral controller


Integral controller, derivative controller


Derivative controller, integral controller


52. The ac motor used in servo application is a


Single phase induction motor


Two phase induction motor


Three phase induction motor


Synchronous motor


53. A block with transfer function is connected in cascade to a zero order hold. The sampled data transfer function of this discrete time system is:

<img src='./qimages/4189-53.jpg'>


54. A function is defined as:

<img src='./qimages/4189-54.jpg'>


It was found that when this signal is applied to the system, the system output as t infinity


The system is asymptotically stable


The system is unstable


The system is marginally stable


The stability of the system cannot be judged from the information given


55. The first two rows of Routh's tabulation of a third order equation are as follows:

s3 2 2

s2 4 4

This means there are:·


Two roots at s =±j and one root in right half s-plane


Two roots at s =±j and one root in left half s-plane


Two roots at =±j2 and one root in right half s-plane


Two roots at s =±j2 and one root in left half s-plane


56. The transfer function of a system is given as 100/S2+20s+100



An over damped system


An under damped system


An critically damped system


An unstable system


57. A system with zero initial conditions has the closed loop transfer function. The system output is zero at the frequency:


0.5 rad/sec


1 rad/sec


2 rad/sec


4 rad/sec



58. When subject to a unit step input, the closed loop control system shown in the figure given below will have a steady state error of

<img src='./qimages/4189-58.jpg'>











(D)0.5


59. For the equation s3-4s2 S the number of roots in the left half of s-plane will be


Zero


One


Two


Three


60. The Nyquist plot of loop transfer function of a closed loop control system passes through the point j0) in the GsHs plane. The phase margin of the system is:
















61. The limiting error of measurement of power consumed by the current passing through a resistance are ± 1.5% and ± respectively. Then the limiting error of measurement of resistance will be


±0.5%


±0.1%


±0.25%


±3.5%


62. A CRO screen has ten divisions on the horizontal scale. If a voltage signal 5 sin(314t is examined with a line base setting of 5m sec/div, the number of cycles of signal displayed on the screen will be


0.5 cycle


2.5 cycles


5 cycles


10 cycles


63. The number of comparators needed in a parallel conversion type 8-bit analog to digital convertor is








(C)255


(D)256


64. An LVDT is used to measure displacement. The output of the LVDT is connected to a voltmeter of range 0 to 5 V through an amplifier having a gain of 250. For a displacement of 0.5 mm, the output of the LVDT is 0.5 mV. The sensitivity of the instrument would be:


0.1 V/mm


0.5V/mm


1V/mm


5V/mm


65. For the ac bridge shown in the figure at balance, the value of Rd, Ld and Qd will be respectively:

<img src='./qimages/4189-65.jpg'>


66. The velocity of flow using Snell's law of refraction applicable to sound waves is:

<img src='./qimages/4189-66.jpg'>


67. For gas pressure below 1mmHg,the thermal conductivity of gas is

(A)Independent of pressure


(B)Dependent of pressure


(C)Independent of volume


(D)Dependent of volume


68. In a digital voltmeter, the oscillator frequency is 400 KHz and ramp voltage falls from 8 V to 0 V is 20 msec. The number of pulses counted by the counter is



(A)800


(B)2000


(C)4000


(D)8000


69. The fact as to how closely the instrument reading follows the measured variables is called the:


(A)Precision


(B)Fidelity


(C)Accuracy·


(D)Sensitivity


70. The ratio and phase angle errors in potential transformer may be reduced by:


Increasing the exciting current


Increasing the resistance and leakage reactance in the transformer


By not employing turns compensation


None of the above


71. A dual trace CRO has a number of time base circuit of


1


2


3


4


72. The deflection of a moving coil galvanometer becomes one-fourth when shunted by 20 ohms resistance. The resistance of the galvanometer is:


10


40


60


50


73. A galvanometer with a resistance of G ohms is shunted by a resistance of S ohms. The resistance to be added for the current to remain unchanged is


G











74. The term artificial ageing in instruments is associated with:


Springs


Permanent Magnet


Damper


Both and


75. Which one of the following DVM has excellent noise rejection feature?


Ramp type DVM


Dual slope type DVM


Successive approximation type DVM


Flash type DVM


76. By saying that the electrostatic field is conservative, we do not mean that:


is the gradient of a scalar potential


(B)Curl is identically zero


(C)The work done in a closed path inside the field is zero


(D)The potential difference between the two points is zero


77. <img src='./qimages/4189-77.jpg'> in a given material, the material is said to be


Linear


Isotropic


Linear and homogeneous


Linear and Isotropic


78. Which of the following potential does not satisfy Laplace's equation?


5


rcos pie


V=pcos pie+10


10xy


79. In a certain medium, electric field E=10cos (108t-3y)^ax v/m. What type of medium is it?


Free space


Perfect dielectric


Lossless dielectric


Perfect conductor


80. In the free space, magnetic field intensity at any point pie, is given by H=2 p2 pie the current density at p 2m will be


^az A/m2


^az A/m2


^az A/m2





81. For the lossless transmission line which of the following option is correct for attenuation constant a and phase constant beta

<img src='./qimages/4189-81.jpg'>


82. Identify which of the following expressions are not Maxwell's equations for time varying fields:

<img src='./qimages/4189-82.jpg'>


83. A loop is rotating about the y-axis in a magnetic field Bo sin wt ^ax wb/m2. The voltage reduced in the loop is due to:


Motional emf


Transformer emf


A combination of motional and transformer emf


None of the above


84. In cylindrical coordiriates the equation <img src='./qimages/4189-84.jpg'> is called:


Laplace's equation


Helmholtz's equation


Maxwell's equation


Poisson's equation


85. <img src='./qimages/4189-85.jpg'>

86. Volume charge density in the free space is given by src='./qimages/4189-86.jpg'>


4pieC


-pieC


2pieC


0C



87. Dielectric strength of a material depends on


Moisture content


Temperature


Thickness


All of the above


88. Which of the following is a vector quantity?


Relative permeability


Magnetic field intensity


Flux density


Magnetic potential


89. "The total electric flux through any closed surface surrounding charges is equal to the amount of charge enclosed." The above statement is associated with:


Coulomb's Square Law


Gauss' Law


Maxwell's First Law


Maxwell's Second Law


90. A field line and an equipotential surface are:


Always parallel


Always at 90°


Inclined at any angle a


None of the above