Question

If the number of turns per unit length of a coil of solenoid is doubled, the self-inductance of the solenoid will

• A. Remain unchanged
• B. Be halved
• C. Be doubled
• D. Become four times

Answer 1

Answer: (D)

Become four times

Answer 2

Self inductance of a solenoid $= \mu_{0}n^{2}Al$

Where n is the number of turns per length

$\therefore$Self inductance is directly proportional to $n^{2}$ self inductance becomes 4 times when n is doubled.