Question

A uniform conducting wire $A B C$ has a mass of $10 \,g$. A current of $2 \,A$ flows through it. The wire is kept in a uniform magnetic field $B=2\, T$. The acceleration of the wire will be

• A. Zero
• B. $12 \,ms ^{-2}$
• C. $1.2 \times 10^{-3}\, ms ^{-2}$
• D. $0.6 \times 10^{-3}\, ms ^{-2}$

Answer 1

Answer: (B)

Force on wire $A B C$ will be same as force on wire $A C$
using $F=i(\vec{I} \times \vec{B})$
$F =2\left(\frac{3}{100}\right)(2) \sin 90^{\circ} $
$=12 \times 10^{-2} N $
$a=\frac{F}{m} =\frac{12 \times 10^{-2}}{10^{-2}}=12 \,m / s ^{2}$