Question

A uniform conducting wire $ABC$ lying in $XY$ plane has a mass of $10g$. A current of $2A$ flows through it. The wire is kept in a uniform magnetic field $B=2T$ which acceleration of the wire is:

• A. $Zero$
• B. $12m/s^2$ and along postive $Y-$axis
• C. $1.2\times {10}^{-3}m/s^2$ along postive $Y-$axis
• D. $0.6m/s^2$ and along positive $X-$axis

Answer 1

The correct option is B $12m/s^2$ and along postive $Y-$axis

Given that,

Mass $m=10g$

Current $i=2A$

Magnetic field $B=2T$

Now, force action on the wire $AC$

$F=Bil\sin \theta$

$F=2\times 2\times 3\times {10}^{-2}\sin {90}^0$

$F=12\times {10}^{-2}N$

Now, the acceleration is

$F=ma$

$a=\frac{F}{m}$

$a=\frac{12\times {10}^{-2}}{10\times {10}^{-3}}$

$a=12m/s^2$

Hence, the acceleration is $12m/s^2$ along positive y axis