For a certain dynamometer ammeter the mutual inductance (M) varies with deflection θ° as M = -6 cos (θ + 30°) mH. Find the deflecting torque produced a direct current of 50 mA corresponding to a deflection of 60°.
1
10 N-m
2
20 N-m
3
15 μN-m
4
1.5 μNm