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Question:

A rectangular coil (dimension 5cm×2.5cm) with 100 turns, carrying a current of 3A in the clockwise direction is kept centered at the origin and in the X-Z plane. A magnetic field of 1T is applied along the X-axis. If the coil is tilted through 45° about the Z-axis, then the torque on the coil is:

0.55Nm

0.27Nm

0.38Nm

0.42Nm

Solution:

Correct option is B. 0.27Nm
|τ|=|M×B|
τ=NI×A×B×sin 45°=0.27Nm