Student Login

Home›Chapters›Dual Nature of Radiation and Matter PYQs›Photoelectric Effect: Einstein's Equation›Question 112

MHT CET 2021 (22 Sep, Shift 1) · Photoelectric Effect: Einstein's Equation

Photoelectric Effect: Einstein's Equation question from MHT CET 2021 (22 Sep, Shift 1)

Q112MHT CET 2021 · 22 SEP · SHIFT 1Medium

Photoelectric Effect: Einstein's Equation

When a light of wavelength ' $\lambda$ ' falls on the emitter of a photocell, maximum speed of emitted photoelectrons is ' $V$ '. If the incident wavelength is changed to $\frac{2\lambda}{3}$ , maximum speed of emitted photoelectrons will be

Show answer and solution

Answer: (c)

$\frac{1}{2}mV^2 = \frac{hc}{\lambda} - \phi$
At $\frac{2\lambda}{3}$ : $\frac{1}{2}mV'^2 = 1.5\frac{hc}{\lambda} - \phi = 1.5\left(\frac{hc}{\lambda} - \phi\right) + 0.5\phi$
So $V'^2 > 1.5V^2 \Rightarrow V' > V(1.5)^{1/2}$
So the answer is (c) greater than $V(1.5)^{1/2}$ .

Report a mistake

More questions on Photoelectric Effect: Einstein's Equation

When wavelength of incident radiation on the metal surface is reduced from ' λ₁ ' to ' λ₂…MHT CET 2021 (23 Sep, Shift 1)
Photoemission from metal surface takes place for frequencies ' v₁ ' and ' v₂ ' of…MHT CET 2021 (21 Sep, Shift 2)
Photoelectrons are emitted when photons of energy 4.2 eV are incident on a photosensitive…MHT CET 2021 (20 Sep, Shift 2)
The radiation corresponding to 3 → 2 transition of a hydrogen atom falls on a gold…JEE Main 2021 (20 Jul, Shift 1)
A light beam of wavelength 500 nm is incident on a metal having work function of 1.25 eV…JEE Main 2021 (25 Jul, Shift 2)
If the maximum kinetic energy of emitted electrons in photoelectric effect is 3.2 × 10⁻¹⁹…MHT CET 2020 (19 Oct, Shift 2)
The light of wavelength λ incident on the surface of metal having work function φ emits…MHT CET 2020 (16 Oct, Shift 2)
The maximum velocity of the photoelectron emitted by the metal surface is v. Charge and…MHT CET 2020 (16 Oct, Shift 1)