Answer:
(B² x e x d²) / V = M
Explanation:
Under electric field by potential gradient if K is the kinetic energy imparted to
the charged particle
K = 1/2 M u² = V x 2e
When charged particle enters the magnetic field with velocity u , it travels on circular path with radius d . So
centripetal force = magnetic force
M u² / d = B x 2e x u
u = (B x 2e x d) / M
Putting this value of u in the relation above
m (B² x 4e² x d²) / 2M² = V x 2e
(B² x 4e² x d²) / V x 2e = 2 M
(B² x e x d²) / V = M