Q144 / 155 · WBJEE 2025 · Physics
Consider a particle of mass 1 gm and charge 1.0 Coulomb is at rest. Now the particle is subjected to an electric field $E(t)=E_0 \sin \omega t$ in the $x$-direction, where $E_0=2$ Newton/Coulomb and $\omega=1000 \mathrm{rad} / \mathrm{sec}$. The maximum speed attained by the particle is
- A2 m/sec
- Correct answerB4 m/sec
- C6 m/sec
- D8 m/sec
Solution
$V_{\max }=\frac{1}{m} \int_0^{\frac{T}{2}} F d t,=\frac{1}{m} \int_0^{\frac{T}{2}} q E_0 \sin (\omega t) d t$
$=\frac{2 \mathrm{qE}_0}{\mathrm{~m} \omega}=4 \mathrm{~m} / \mathrm{s}$
Hence, the correct answer is option: 'B'.