A square coil of side and 100 turns is free to rotate about the side which is fixed…

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

Problem

A square coil

ABCD

of side

0.20\,\text{m}

and 100 turns is free to rotate about the side

CD

which is fixed to a horizontal torsion spring. The torsion spring offers a restoring couple

k\phi

where

k=0.050\,\text{N\,m\,/rad}

and

\phi

is the angular deflection of the coil from its initial vertical position. The coil is placed in a uniform magnetic field of

0.30\,\text{T}

directed perpendicular to the side

CD

and carries a current

I

. (a) Establish the equation that relates the angular deflection

\phi

to the current

I

under static equilibrium. (b) For a steady current of

2.5\,\text{A}

, calculate the value of

\phi

. (c) If the current is suddenly reversed in direction while its magnitude remains the same, state and explain qualitatively what will happen to the deflection of the coil. Will the magnitude of

\phi

change?

Related theory

Browse the problem library