KCET2024PhysicsMagnetic Effects of Current
The magnetic field at the centre of a circular coil of radius R carrying current I is 64 times the magnetic field at a distance x on its axis from the centre of the coil. Then, the value of x is
Options
- AR 4 15
- BR 3
- CR 4
- DR 15
Correct answer
D. R 15
Step-by-step solution
Given, B_ centre =64 B_ axis ₀ I 2 R =64 ₀ I R^2 2 (R^2+x^2 )^ 3 2 (R^2+x^2 )^ 3 2 =64 R^3=(4 R)^3 (R^2+x^2 )^ 1 2 =4 R R^2+x^2=16 R^2 15 R^2=x^2 x= 15 R=R 15