Question

A straight wire of length $0.5$ $\text{m}$ and carrying a current of $1.2$ ampere is placed in uniform magnetic field of induction $2$ Tesla. The magnetic field is perpendicular to the length of the wire. The force on the wire is

• A. $1.2$ $\text{N}$
• B. $2.4$ $\text{N}$
• C. $3.0$ $\text{N}$
• D. $2.0$ $\text{N}$
  

Answer 1

The correct option is A $1.2$ $\text{N}$

Given:
$l=0.5$ $\text{m}$
$i=1.2$ $\text{A}$
$B=2$ $\text{T}$
The magnetic force on wire is given by
$F=i(l\times B)$
$F=ilB\sin \theta$
Where $\theta =$ Angle between $l$ and $B$
According to question , $\theta ={90}^{\circ }$
As $\sin {90}^{\circ }=1$
$\therefore$$F=1.2\times 0.5\times 2$
$F=1.2$ $\text{N}$
Hence, option $\left(B\right)$ is correct option.