Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Dual Nature of Radiation and Matter

Question:

A photon has the same wavelength as the de-Broglie wavelength of electron. Given that c = speed of light and v = speed of electron. Which of the following relation is correct? [Here $E_e$ =Kinetic energy of electron, $E_{ph}$ = energy of photon, $p_e$ =momentum of electron and $p_{ph}$ =momentum of photon]

Options:

$\frac{E_e}{E_{ph}}=\frac{2c}{v}$

$\frac{E_e}{E_{ph}}=\frac{v}{2c}$

$\frac{p_e}{p_{ph}}=\frac{2c}{v}$

$\frac{p_e}{p_{ph}}=\frac{c}{2v}$

Correct Answer:

$\frac{E_e}{E_{ph}}=\frac{v}{2c}$

Explanation:

Given,

$λ_{ph}=λ_e$

$∴\frac{h}{p_{ph}}=\frac{h}{p_e}$

$∴p_{ph}=p_e$

$∴\frac{E_{ph}}{c}=\frac{2E_e}{v}$

$∴\frac{E_e}{E_{ph}}=\frac{v}{2c}$