Question

A cathode ray tube has a potential difference of 100V between the cathode and anode. The speed acquired by the electron in going from cathode to anode will be nearest to:

Answer 1

electron's v
energy will be 100ev then compare with 1/2mvsquare

Answer 2

Explanation:

A cathode ray tube has a potential difference of 100 V between the cathode and anode. We have to find the speed acquired by the electron in going from cathode to anode.

According to work energy theorem :

$\dfrac{1}{2}mv^2=eV$

$v=\sqrt{\dfrac{2eV}{m}$

$v=\sqrt{\dfrac{2\times 1.6\times 10^{-19}\times 100}{9.1\times 10^{-31}}$

v = 592999.5 m/s

or

$v=5.9\times 10^6\ m/s$

Hence, this is the required solution.