Explanation:
n=50,r=0.02mn=50,r=0.02m,
I=5AandB=0.20TI=5AandB=0.20T
τismaxiμmwhensinθ=90∘τismaxiμmwhensinθ=90∘
τmax=niabsin90∘=mbτmax=niabsin90∘=mb
=50×5×3.14×4×10−4×2×10−1=50×5×3.14×4×10-4×2×10-1
=6.28×10−2Nm=6.28×10-2Nm
Given τ=12×τmaxτ=12×τmax
⇒sinsinθ=12⇒sinsinθ=12 or sinθ=30∘sinθ=30∘
=∠betweenareavar→randmag≠ticfield=∠betweenareavar→randmag≠ticfield.
So angle between magnetic field and the plane of the coil
=90∘−30∘=60∘=90∘-30∘=60∘.