An electron is moving in a circular path under the influence of a transverse magnetic field of $3.57 \times 10^{- 2}$ T. If the value of $e / m$ is $1.76 \times 10^{11} C k g^{- 1}$ , the frequency of revolution of the electron is

see full answer

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

1 GHz

62.8 MHz

100 MHz

6.28 MHz

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Here, $B = 3.57 \times 10^{- 2} T, \frac{e}{m} = 1.76 \times 10^{11} {Ckg}^{- 1}$

Frequency of revolution of the electron,

$v = \frac{1}{T} = \frac{v}{2 π r}$ ……..(1)

$Also, \frac{m v^{2}}{r} = e v B \Rightarrow \frac{v}{r} = \frac{e B}{m}$ ……….(2)

From eqns. (i) and (ii)

$v = \frac{1}{2 π} \times \frac{e B}{m} = \frac{1}{2 \times 3.14} \times 1.76 \times 10^{11} \times 3.57 \times 10^{- 2}$

$= 10^{9} Hz = 1 GHz$

Watch 3-min video & get full concept clarity