WBJEE 2017 Physics Solved Paper

A proton is moving with a uniform velocity of 106 ms–1 along the Y-axis, under the joint action of a magnetic field along Z-axis and an electric field of magnitude 2×104 Vm–1 along the negative X-axis. If the electric field is switched off, the protonstarts moving in a circle. The radius of the circle is nearly (given :

e

m

ratio of proton = 108‌CKg−1 )