First slide

Magnetic force

Question

An electron is projected with velocity $V_{0}$ in a uniform electric field E perpendicular to the field. Again it is projected with velocity $V_{0}$ perpendicular to a uniform magnetic field B. If $r_{1}$ is initial radius of curvature just after entering in the electric field and $r_{2}$ is initial radius of curvature just after entering in magnetic field then $r_{1} / r_{2}$ is

Moderate

A

$\frac{B {V_{o}}^{2}}{E}$
B

$\frac{B}{E}$
C

$\frac{E V_{o}}{B}$
D

$\frac{B V_{o}}{E}$

Solution

In electric field, electrostatic force provides centripetal force , $\frac{m {V_{o}}^{2}}{r_{1}} = E q \Rightarrow r_{1} = \frac{m {V_{o}}^{2}}{E q} .............. (1)$
In magnetic field, magnetic force provides centripetal force , $B q V_{o} = \frac{m {V_{o}}^{2}}{r_{2}} \Rightarrow r_{2} = \frac{m V_{o}}{B q} ................. (2)$
$\frac{(1)}{(2)} \Rightarrow \frac{r_{1}}{r_{2}} = \frac{B V_{o}}{E}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App