A beam of fast moving electrons having cross-sectional area A falls normally on a flat surface. The electrons are absorbed by the surface and the average pressure exerted by the electrons on this surf

Question

A beam of fast moving electrons having cross-sectional area A falls normally on a flat surface. The electrons are absorbed by the surface and the average pressure exerted by the electrons on this surface is found to be P. If the electrons are moving with a speed v, then the effective current through any cross-section of the electron beam is

Options:

Answer:

A

Solution:

Momentum transfer gives

$P A = \dot{N} m v i = e \dot{N} i = \frac{A P e}{m v}$

TestHub · Accepted Answer

Momentum transfer gives ​ P A = N ˙ m v ​ i = e N ˙ ​ i = m v A P e ​ ​

Physics - Modern Physics Question with Solution | TestHub

Options:

Doubts & Discussion