A circular coil 200 cm in diameter and containing nine loops

A circular coil 20.0 cm in diameter and containing nine loops lies flat on the ground. The Earth\'s magnetic field at this location has magnitude 8.00 × 10^5 T and points into the Earth at an angle of 60.0 degrees below a line pointing due north. If a 6.90 A clockwise current passes through the coil.

Determine the torque on the coil. ( unit --> m×N )

Incorrect answers:

ANSWER 1:

2.99103

ANSWER 2:

47.8105

ANSWER 3:

47.8105

Solution

the torque on the coil is,

    t = NIABsin@

     = (9)(6.9)(pi)(0.1^2)(8.00 × 10^5)sin60^o

     = 1.35e-4 m.N