Question
A 50 turn coil as shown in the figure below carries of 2 A in a magnetic field B = 0.25 Wb m –2. Find the torque acting on the coil. In what direction will it rotate?
Solution
Number of turns on the coil, N = 50
Current carried by the coil, I= 2A
Magnetic field,B = 0.25 Wb m –2
Torque acting on the coil, = ?
As seen in the fig.
The sides AB and DC are along the field lines hence, the force on each side is zero.
The force on each vertical wire is given as
τ = BINA sin θ
τ = 0.25 x 2 x 50 x 0.12 x 0.1 sin θ
= 0.3 N-m (clockwise direction)
