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Question
A circular coil of radius 2.0 cm has 500 turns and carries a current of 1.0 A. Its axis makes an angle of 30° with the uniform magnetic field of magnitude 0.40 T that exists in the space. Find the torque acting on the coil.
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Solution
Given:
No. of turns of the coil, n = 500
Magnetic field intensity, B = 0.40 T = 4 × 10−1 T
Radius of the coil, r = 2 cm = 2 × 10−2 m
Magnitude of current, i = 1 A
Angle between the area vector and magnetic field, θ = 30°
Torque acting on the coil,
τ = niABsinθ
Here, A is the area of the coil.
τ = 500 × 1 × 3.14 × 4 × 10−4 ×4×10−1 × 1/2
= 12.56 × 10−2
= 0.1256 = 0.13 N-m
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