Question

A uniform magnetic field B exists in the region between x = 0 and x = 3R/2 (region 2 in the figure) pointing normally into the plane of the paper. A particle with charge +Q and momentum p directed along x-axis enters region 2 from region 1 at point P₁ (y = -R). Which of the following option(s) is/are correct?

(A) For B > 2/3 p/QR , he particle will re-enter region 1

(B) For B = 8/13 p/QR , the particle will enter region 3 through the point P₂ on x-axis

(C) When the particle re-enters region 1 through the longest possible path in region 2, the magnitude of the change in its linear momentum between point P₁ and the farthest point from y-axis is p / √2

(D) For a fixed B, particles of same charge Q and same velocity v, the distance between the point P₁ and the point of re-entry into region 1 is inversely proportional to the mass of the particle

Answer 1

(A) For B > 2/3 p/QR , he particle will re-enter region 1

(B) For B = 8/13 p/QR , the particle will enter region 3 through the point P₂ on x-axis