Q. A particle of specific charge $\frac{q}{m}=\mathrm{\pi C}/\mathrm{kg}$ is projected from the origin towards positive x—axis with a velocity of 10 m/s in a uniform magnetic field $\overrightarrow{B}=-2\hat{k} T.$ The velocity $\overrightarrow{v}$ of particle after time $t=\frac{1}{12}s$ will be ( in m/s )
1. $5\left[\hat{i}+\sqrt{3}\hat{j}\right]$
2. $5\left[\sqrt{3}\hat{i}+\hat{j}\right]$
3. $5\left[\sqrt{3}i-\hat{j}\right]$
4. $5\left[\hat{i}+\hat{j}\right]$