TS ECET EEE 2016-8

1.Superposition theorem can be applied only to circuits havein ______ elements

A. Non linear
B. Passive
C. Linear and bilateral
D. Resistance

Answer : Linear and bilateral
Explain:-

2. The combined inductance of two coils connected in series is 0.6 H or 0.1 H depending on the relative directions of currents in the coils. If one of the coils has a self inductance of 0.2 H, the self Inductance of other coil is

A. 0.5 H
B. 0.35 H
C. 0.15 H
D. 0.25 H

Answer : 0.15 H
Explain:-

3. The diameter of a wire is reduced to one half keeping the length constant then the new resistance will be

A. Half of the original
B. Four times the original
C. Twice the original
D. One-fourth of the original

Answer : Four times the original
Explain:-

4. Three resistors. each of RN. are connected to form a triangle. The equivalent resistance between any two terminals will be

A. (3/2)R ohm
B. (2/3)R ohm
C. R ohm
D. 3R ohm

Answer : (3/2)R ohm
Explain:-

5. Four 100 W bulbs are connected in parallel across 200 V supply line. If one bulb gets fused

A. No bulb will glow
B. All the four bulbs will glow
C. Rest of the three bulbs will glow
D. one bulb will glow

Answer : Rest of the three bulbs will glow
Explain:-

6. Four capacitors having capacitances of 5microF, 10 microF, 15 microF and 20 F are connected in parallel across 600 V mains. The capacitor having least charge will be

A. 5 microF
B. 10 microF
C. 15 microF
D. 20 microF

Answer : 5 microF
Explain:-

7. Equalizer rings are required in a lap wound DC machine

A. to improve commutation
B. to filter out harmonics
C. to prevent the flow of circulating current through brushes
D. to reduce armature reaction

Answer : to prevent the flow of circulating current through brushes
Explain:-

8. A DC series motor has linear magnetization and negligible armature resistance. If 'T Is torque, the motor speed is

A. Directly proportional to √T
B. Inversely proportional to √T
C. Directly proportional to T
D. Inversely proportional to T

Answer : Inversely proportional to √T
Explain:-

9. In a DC generator, emf due to residual flux is fed back to the shunt winding positively. Why does the no load voltage build up to a finite steady value

A. because of field winding inductance
B. because of magnetic saturation
C. because of field winding resistance
D. beacause of eddy current loss in pole shoes

Answer : because of magnetic saturation
Explain:-

10. Inter-poles help commutation in a DC machine by

A. Cancelling the armature reaction mmf
B. Aiding the main poles
C. By causing statically induced emf in the coils undergoing commutation
D. By causing dynamically induced emf in the coil undergoind commutation

Answer : By causing dynamically induced emf in the coil undergoind commutation
Explain:-