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 $A$ increases
• B. $l$ decreases and $A$ increases
• C. $l$ increases and $A$ decreases
• D. Both $l$ and $A$ decreases

Answer 1

The correct option is B $l$ decreases and $A$ increases

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 decreases and A increases.