A square coil of turns and side is free to rotate about a vertical axis through its centre

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Magnetism and Electromagnetism · Magnetism and Electromagnetism

Problem

A square coil of

50

turns and side

0.10\,\text{m}

is free to rotate about a vertical axis through its centre. The coil carries a current of

2.0\,\text{A}

and is placed in a horizontal uniform magnetic field of

0.30\,\text{T}

. It is attached to a torsion spring that exerts a restoring torque of

5.0\times10^{-3}\,\text{N m}

per degree of twist. Find the steady angular deflection of the coil from its zero-torque position. (a)

60^{\circ}

(b)

30^{\circ}

(c)

45^{\circ}

(d)

15^{\circ}