JEE Advanced2017PhysicsMagnetic Effects of CurrentActual
A uniform magnetic field B exists in the region between x = 0 and x = 3 R 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 P 1 y = - R . Which of the following option(s) is/are correct?
Options
- AFor B = 8 13 p Q R , the particle will enter region 3 through the point P 2 on x -axis
- BFor B > 2 3 p Q R , the particle will re-enter region 1
- CFor a fixed B, particles of same charge Q and same velocity v , the distance between the point P 1 and the poi
- DWhen the particle re-enters region 1 through the longest possible path in region 2, the magnitude of the chang
Correct answer
A. For B = 8 13 p Q R , the particle will enter region 3 through the point P 2 on x -axis
Step-by-step solution
For B = 8 13 p Q R , radius of path R ' = p O . B = p × 13 Q R Q 8 p = 13 8 R Using pythagorous theorem, y = 5 R 8 ∴ particle will enter region 3 through point P 2 for B > 2 3 p Q R Radius of path 3 P Q R Q 2 p = 3 2 R ∴ Particle will not enter in region 3 and will re-enter region 1 Charge on momentum = 2 p . When particle enters region 1 between entry point and farthest point from y-axis.