2. What should theta be in order to get maximum emf?

A. 0°
B. 90°
C. 180°
D. 45°

Answer: B

The value of θ should be 90^{0} in order to get maximum emf because e = Blvsin(θ) and sin is maximum when θ is 90^{0}.

3. Calculate the maximum emf when the velocity is 10m/s, the length is 3m and the magnetic field density is 5T.

A. 150V
B. 100V
C. 300V
D. 0V

Answer: A

We know that:

e_{max} = Bvl

Substituting the values from the given question, we get e = 150V.

4. When a coil is rotated in a magnetic field, the emf induced in it?

A. Is maximum
B. Is minimum
C. Continuously varies
D. Remains constant

Answer: C

When a coil is rotated in a magnetic field, the cross−sectional area varies due to which the number of flux lines crossing it varies, which causes the emf to vary continuously.

5. EMF is zero if the angle between velocity and length is ________

A. 0°
B. 90°
C. 270°
D. 45°

Answer: A

If the angle between velocity and length is zero, sinθ = 0

So, e = Bvlsinθ = 0.

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6. In an A.C. generator, increase in the number of turns in the coil _________

A. Increases emf
B. Decreases emf
C. Makes the emf zero
D. Maintains the emf at a constant value

Answer: A

In an A.C. generator, the emf increases as the number of turns in the coil increases because the emf is directly proportional to the number of turns.

7. The number of cycles that occur in one second is termed as ___________

A. Waveform
B. Frequency
C. Amplitude
D. Period

Answer: B

The number of cycles that occur in one second is known as frequency. It is the reciprocal of the time period.

8. The variation of a quantity such as voltage or current shown on a graph is known as ___________

A. Waveform
B. Peak value
C. Instantaneous value
D. Period

Answer: A

The variation of a quantity, which is voltage or current in this case, shown on a graph with the x−axis as time is known as a waveform.

9. The duration of one cycle known as _________

A. Waveform
B. Peak value
C. Instantaneous value
D. Period

Answer: D

The duration of one cycle is known as a period. A function that repeats the same waveform at equal intervals of time is known as a periodic function.

10. The repetition of a variable quantity, recurring at equal intervals, is known as ___________

A. Waveform
B. Instantaneous value
C. Cycle
D. Period

Answer: C

The repetition of a variable quantity, recurring at equal intervals, is known as Cycle.

Each repetition of a variable quantity, recurring at equal intervals, is termed a cycle.