Question

Two concentric circular coils of six turns each are situated in the same plane. Their radii are 10 cm and 20 cm and they carry respectively 0.1 A and 0.2 A current in same direction. The magnetic field in tesla at the centre is ______.

Options

• `µ_0/6`

• `12µ_0`

• `5/2µ_0`

• `6µ_0`

Answer 1

Two concentric circular coils of six turns each are situated in the same plane. Their radii are 10 cm and 20 cm and they carry respectively 0.1 A and 0.2 A current in same direction. The magnetic field in tesla at the centre is 6µ₀.

Explanation:

`"B"=("µ"_0 "n"_1"I" _1)/(2"r"_1)+("µ"_0 "n"_2"I" _2)/(2"r"_2)`

`="µ"_0/2 [(6xx0.10)/0.10+(6xx0.10)/0.20]= 6"µ"_0`