Question

A 100 coil shown in figure carries a current of 2 A in a magnetic field B=0.2wb/$m^2$ The torque acting on coil is

• A. 0.32 N-m tending to rotate the side AD out of the page
• B. 0.32 N-m tending to rotate the side AD into the page
• C. 0.0032 N-m tending to rotate the side AD out of the page
• D. 0.0032 N-m tending to rotate the side AD into the page

Answer 1

The correct option is A 0.32 N-m tending to rotate the side AD out of the page

$\text{Given:-}$ Number of turns on the coil $N=100$

Current carried by coil, $I=2A$

Magnetic field, $B=0.2Wb/m^2$

$\text{Solution:-}$

Side AB and side DC are along the magnetic field line, hence force on each side is zero

The force on each vertical wire is given by

$\tau =BINAsin\theta$

$\tau =0.2\times 2\times 100\times (0.1\times 0.08)$

$\tau =0.32N\cdot m$

$rotatethesideADoutofthepage$

$\text{Hence the correct option is A}$