NEET Physics Question - Modern Physics - Photoelectric Effects and deBroglie Equation

Assertion (A): A photon and an electron both have energy \(50\text{ eV}\). Both have different wavelengths.

Reason (R): Wavelength depends on energy and not on mass.

Both (A) & (R) are true and the (R) is the correct explanation of the (A)

Both (A) & (R) are true but the (R) is not the correct explanation of the (A)

(A) is true but (R) is false

Both (A) and (R) are false

Solution:

For a photon, wavelength is \(\lambda_p = hc/E\). For an electron, de Broglie wavelength is \(\lambda_e = h/\sqrt{2mE}\). Since their formulas are different and \(\lambda_e\) depends on mass \(m\), their wavelengths will be different for the same energy. So (A) is true. Reason (R) is false because an electron's de Broglie wavelength depends on its mass.

Rankers Physics

Wavelength of Photon vs. Electron

Solution:

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