AC Generator — Practice Quiz

Question 1

A 100-turn coil of area 0.05 m² rotates at 50 rad/s in B = 0.2 T. Peak EMF:

Accepted Answer

50 V

Answer

100 V

Answer

5 V

Answer

10 V

Question 2

If rotation speed of the generator coil doubles, what happens to peak EMF and frequency?

Accepted Answer

Both double

Answer

Both halve

Answer

EMF doubles, f same

Answer

f doubles, EMF same

Question 3

A 2-pole generator must spin at what speed to give 50 Hz?

Accepted Answer

3000 rpm

Answer

1500 rpm

Answer

750 rpm

Answer

6000 rpm

Question 4

EMF induced in a rotating coil is zero when:

Accepted Answer

Coil plane is perpendicular to B (area vector parallel to B)

Answer

Coil plane is parallel to B (area vector perpendicular to B)

Answer

ω is zero

Answer

B is zero

Question 5

Slip rings vs commutator: the difference is:

Accepted Answer

Slip rings give AC, commutator rectifies it to DC

Answer

Slip rings give DC, commutator gives AC

Answer

Both give AC

Answer

Both give DC