Question

The self inductance L of a solenoid of length l and area of cross-section A, with a fixed number of turns N increases as

• A. l and A increase
• B. l decreases and A increases.
• C. l increases and A decreases.
• D. Both l and A decrease.

Answer 1

Answer: (B)

l decreases and A increases.

Answer 2

The self inductance L of a solenoid of length l and area of cross section A with fixed number of turns N is

$L = \frac{\mu_{0}N^{2}A}{l}$

So, L increases when l decrease and A increase.