Appeared in: 2025 (3 sets)
A charged particle gains a speed of $10^6 \text{ ms}^{-1}$, when accelerated from rest through a potential difference $10\text{ kV}$. It enters a region of magnetic field of $0.4\text{ T}$ such that $\vec{v} \perp \vec{B}$. The radius of circular path described by it is :
(A) $2.5\text{ cm}$
(B) $5\text{ cm}$
(C) $8\text{ cm}$
(D) $10\text{ cm}$