Question

When the number of turns in a coil is tripled without any change in the length of the coil, its self-inductance ______

Options

• becomes 3 times.

• becomes 9 times.

• gets halved.

• remains unchanged.

Answer 1

When the number of turns in a coil is tripled without any change in the length of the coil, its self-inductance becomes 9 times.

Explanation:

L = `(mu_0"N"^2"A")/1`

where N is the total number of turns.

As L ∝ N²

∴`"L"_2/"L"_1 = ("N"_2/"N"_1)^2 = (3)^2`

∴ L₂ = 9L₁