WBJEE · Physics · Magnetic Effects of Current
A particle of mass \(\mathrm{m}\) and charge \(\mathrm{q}\) moving with velocity \(\mathrm{v}\) enters region-b form region-a along the normal to the boundary as shown is the figure. Region-b has a uniform magnetic field \(B\) perpendicular to the plane of the paper. Also, region-b has length L. Choose the correct statements :
- A The particle enters region-c only if \(\mathrm{v}>\frac{\mathrm{qLB}}{\mathrm{m}}\)
- B The particle enters region-c only if \(\mathrm{v} < \frac{\mathrm{qLB}}{\mathrm{m}}\)
- C Path of the particle is a circle in region-b
- D Time spent in region -b is independent of velocity v
Answer & Solution
Correct Answer
(D) Time spent in region -b is independent of velocity v
Step-by-step Solution
Detailed explanation
Particle enter region 'c' if Radius is greater than ' \(L\) ' \(\Rightarrow \frac{m V}{q B}>L \Rightarrow V>\frac{q B L}{m}\) \(\because\) B is uniform and \(\overrightarrow{\mathrm{V}} \perp \overrightarrow{\mathrm{B}}\) so. Path is circular in region b…
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