Three solenoid coils of same dimension, same number of turns and same number of layers of windings are taken. Coil 1 with inductance `L_(1)` was would using a wire of resistance `11Omega//m`, coil 2 with inductance `L_(2)` was wound using the similar wire but the direction of winding was reversed in each layer, coil 3 with inductance `L_(3)` was wound using a superconducting wire. The self-inductance of the coils `L_(1),L_(2)` and `L_(3)` are

Options

A. `L_(1)=L_(2)=L_(3)`
B. `L_(1)=L_(2), L_(3)=0`
C. `L_(1)=L_(3),L_(2)=0`
D. `L_(1)gt L_(2)gt L_(3)`

Answer

B

Explanation

The self - inductance of a coil `L=mu_(0)n^(2)Al` where
`mu_(0)=` permeability of air,
n = number of turns per unit length,
A = Area of cross - section and
l = length of the solenoid
This depends on the geometry of the inductor such as cross - sectional area, length and number of turns and not on the material, even if it is made of a super conducting material. If the superconductor is below the ciritical temperature, the current will continuously flow and the inductance may not have the property of inductance any more. `therefore L_(1)=L_(2), L_(3)=0`.