question_answer

Directions : In the following question more than one of the answers given may be correct. Select the correct answer and mark it according to the code:

A charged particle moves with a speed v in a circular path of radius r around a long uniformly charged conductor. If the conductor has a charge per unit length\[\lambda ,\]the particle has mass m and charge q; then (1) \[v\propto \sqrt{q}\]                               (2) \[v\propto \sqrt{\lambda }\] (3) \[v\propto \sqrt{m}\]                             (4) \[v\propto \frac{1}{m}\]

A)  1, 2 and 3 are correct

B)  1 and 2 are correct

C)  2 and 4 are correct

D)  1 and 3 are correct

Correct Answer: B

Solution :

                                  \[=q\frac{\lambda }{2\pi {{\varepsilon }_{0}}r}\] or         \[{{v}^{2}}=(q\lambda /2\pi {{\varepsilon }_{0}}m)\]