## Answer & Solution

**Option A**

21.

Which of the following inductor will have the least eddy current losses?

22.

Find the force acting on a conductor 3m long carrying a current of 50 amperes at right angles to a magnetic field having a flux density of 0.67 tesla

23.

Both the number of turns and the core length of an inductive coil are doubled. Its self-inductance will be

24.

The polarity of the induced voltage can be determined by using the left-hand generator rule.

25.

A conductor 2 meters long moves at right angles to a magnetic field of flux density 1 tesla with a velocity of 12.5 m/s. The induced e.m.f. in the conductor will be

26.

If current in a conductor increases then according to Lenz's law self-induced voltage will

27.

Two coils have inductances of 8 mH and 18 mH and a coefficient of coupling of 0.5. If the two coils are connected in series aiding, the total inductance will be

28.

Two coils have self-inductances of 10 H and 2 H, the mutual inductance being zero. If the two coils are connected in series, the total inductance will be

29.

A coil is wound on iron core which carries current I. The self-induced voltage in the coil is not affected by

30.

Mutually inductance between two magnetically coupled coils depends on