1. For parallel operation of the two alternators, desirable feature is that both should have ?

same reactance

same resistance

more of resistance as compared to synchronous reactance

less of resistance as compared to synchronous reactance

Answer: less of resistance as compared to synchronous reactance

Explanation:


2. less of resistance as compared to synchronous reactance ?

transfer of load

synchronizing

balancing of load

phase sequence

Answer: synchronizing

Explanation:


3. Hydrogen is used in large alternators mainly to ?

reduce distortion of waveform

cool the machine

strengthen the magnetic field

reduce eddy current losses

Answer: cool the machine

Explanation:


4. ln case of turbo alternators the rotor is usually made of ?

cast iron

forged steel

laminated stainless steel

manganese steel

Answer: forged steel

Explanation:


5. Where the terminal voltage of an alternator falls on throwing of the load, it indicates that the load is purely ?

resistive

capacitive

inductive

none of the above

Answer: inductive

Explanation:


6. Harmonic component of generated e.m.f. will be more in ?

short pitch coil

full-pitch coil

long-pitch coil

none of above coils

Answer: full-pitch coil

Explanation:


7. Which of the following is not integral part of synchronous generator system ?

Excitation system

Protection system

Prime mover

Distribution system

Answer: Distribution system

Explanation:


8. In a star connected armature wincing ?

phase voltage contains 3rd harmonic e.m.f. but live voltage does not contain it

phase voltage contains 3rd harmonic e.m.f. ns live voltage also contains third harmonic component

phase voltage does not contain third harmonic e.m.f. as line voltage also does not contain it

none of the above

Answer: phase voltage contains 3rd harmonic e.m.f. but live voltage does not contain it

Explanation:


9. ln which coil the harmonic component of the generated e.m.f. will be more ?

Full pitch coil

Short pitch coil

Long pitch coil

Same in all coils

Answer: Full pitch coil

Explanation:


10. When two alternators are running in exact synchronism, the synchronising power will be ?

unity

zero

sum of the output of two

none of the above

Answer: zero

Explanation: