Question

Two coils have the same number of circular turns and carry the same current. Each rotates in a magnetic field acting perpendicularly to its axis of rotation. Coil 1 has a radius of 4.0 cm and rotates in a 0.21-T field. Coil 2 rotates in a 0.45-T field. Each coil experiences the same maximum torque. What is the radius (in cm) of coil 2

Answer 1

The radius of coil 2 = 2.7 cm

Step-by-step explanation:

The number of coils = 2

It is given that both carry equal current and rotates in the magnetic field.

The given radius of coil 1 = 4.0 cm

Coil 1 rotates = 0.21 T field

Coil 2 rotates = 0.45 T filed.

The radius of coil 2 need to be calculated.

Torque action on dipole is given by
`T =NIABsinθ`

here T1 = T2

`r1^(2) * B1 = r2^(2) * B2 \\r2^(2) = 0.04 * 0.04 * (0.21)/(0.45) \\r2 = 0.027m \ or \ 2.7 cm \\`