Figure shows a schematic view of an electrostatic analyzer. It can sort out charged particles by speed and charge to mass ratio. Spacecraft use such analyzers to characterize charged particles in interplanetary space. Two curved metal plates establish an electric field given by `E=E_(0)(b/r)` where `E_(0)` and b are positive constants with unit of electric field and length. The field points toward the centre of curvature and r is distance from centre. There is no influence of gravity. Proton (change `+e` mass 'm') enters along y-axis and exits along x-axis while moving along a circular path.

Mark the correct option.

Options

A. If `E_(0)` is made larger then in order to maintain same trajectory initial speed has to be decreased.
B. If proton enters closer to the inner surface it will require smaller speed to follow circular trajectory.
C. It does not matter where the protons enter the device it requires same speed to follow circular trajectory.
D. A deuteron (charge`+e` mass 2m)will require greater speed as compared to proton to follow circular trajectory.

Answer

C

Explanation

v is independent of r.