1. The algebraic sum of current flowing towards a junction in an electric circuit is

(a) equal to zero

(b) equal to voltage in a junction

(c) equal to current flowing away from a junction

(d) equal to one

2. Define Kirchoff’s voltage law:-

(a) algebraic sum of currents

(b) algebraic sum of emf’s + algebraic sum of voltage drops = 0

(c) zero

(d) algebraic sum of emf’s - algebraic sum of voltage drops = 0

3. In the circuit 3 shown, the current through the 2Ω resistor is

Figure 3

(a) 0.61

(b) 1.0

(c) 6.1

(d) 0.061

4. The relation between time period and frequency are

(a) T = 20/f

(b) f = 20/T

(c) T α f

(d) T = 1/f

5. A pure inductive coil allows a current of 10 A to flow from a 230v, 50Hz supply. What is the Inductance of thecoil?

(a) 23.5/ ΠΩ

(b) 0.23/ΠΩ

(c) 10/ ΠΩ

(d) 26/ ΠΩ

6. The reactance of a capacitor at 50 Hz is 5 Ω. If the frequency is increased to 100 Hz, the new reactance is

(a) 125Ω

(b) 5Ω

(c) 10 Ω

(d) 2.5 Ω

7. Find the peak to peak value of an ac voltage whose effective value is 50V rms?

(a) 7.07 V

(b) 707.0 V

(c) zero

(d) 70.7 V

8. A coil of 0.06H and 2.5 Ω is connected in series with a 6.8 µF capacitor. What is the power factor of the circuit

(a) 0.8

(b) -0.99

(c) 0.6

(d) 0.99

9. A coil of resistance 100 Ω and 100 µH is connected in series with a 100 PF is connected to a 10V, variable frequencysupply. What is the current through the circuit at resonance.

(a) 0.01A

(b) 1A

(c) 0.1A

(d) 10A

10. A balanced delta connected load of (2+j3) ohms per phase is connected to a balanced 3-phase 440V supply. Thephase current is 10A. Find active power.

(a) 7.26KW

(b) 50KW

(c) 10KW

(d) 100KW

11. A d.c series motor should always be started with load, because it at no-load

(a) will rotate at dangerously high speed

(b) draws a small current

(c) cannot start

(d) will not develop high starting torque

12. A compound generator is to supply a load of 250 lamps, each rated at 100W, 250V. The armature, series and shuntfield resistances are 0.06, 0.04 and 50Ω respectively. What is the value of armature current when connected in shortshunt.

(a) 105.08A

(b) 100A

(c) 100.08A

(d) 105A

13. Which type of motors are used for producing medium starting torque for conveyors?

(a) DC shunt motor

(b) cumulative compound DC motor

(c) DC series motor

(d) differential compound DC motor

14. A 230V dc shunt motor has an armature resistance of 0.3 Ω. Calculate the resistance to be connected in series withthe armature to limit the armature current to 75 A at starting

(a) 3.0667 Ω

(b) 2.7667 Ω

(c) 2 Ω

(d) 0 Ω

15. Which winding of the transformer has large cross-sectional area?

(a) Primary winding

(b) High voltage winding

(c) Secondary winding

(d) Low voltage winding

16. A 4-pole, 1200 rpm alternator generates emf at a frequency of

(a) 50Hz

(b) 60Hz

(c) 40Hz

(d) 25Hz

17. Why single phase Induction motor not self starting?

(a) Because it is not given by3-φ supply

(b) The resistance of the stator winding is very high

(c) inductance of the stator winding is high

(d) pulsating current is incapable of producing a rotating torque in the stationary rotor

18. Moving Iron Instruments are

(a) Dependent of the direction in which the current passes

(b) Independent of the direction in which the current passes

(c) Dependent of the direction in which the voltage passes

(d) independent of the direction in which the voltage passes

19. The force responsible for reduction of oscillations in an ammeter is

(a) controlling force

(b) damping force

(c) deflecting and controlling force

(d) deflecting force

20. Units of Energy are

(a) Joule

(b) meters/sec

(c) Watts

(d) Newton