Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET
Exam
NEET
Subject
Physics
Chapter
Dual Nature of Matter

NEET · Physics · Dual Nature of Matter

The graph between 1 / λ and stopping potential (V) of three metals...

The graph between 1/λ1 / \lambda and stopping potential (V)(V) of three metals having work function ϕ1,ϕ2\phi_1, \phi_2 and ϕ3\phi_3 in an experiment of photoelectric effect is plotted as shown in the figure. Which of the following statement(s) is/are correct? [Here λ\lambda is the wavelength of the incident ray]. The graph between 1 / λ and stopping potential (V) of three metals having work function φ_1, φ_2 and φ_3 in an

Options

  1. ARatio of work functions ϕ1:ϕ2:ϕ3=1:2:4\phi_1: \phi_2: \phi_3=1: 2: 4.
  2. BRatio of work functions ϕ1:ϕ2:ϕ3=4:2:1\phi_1: \phi_2: \phi_3=4: 2: 1.
  3. Ctan⁡θ\tan \theta is directly proportional to hc/eh c / e, where hh is Planck's constant and cc is the speed of light.
  4. DThe violet colour light can eject photoelectrons from metals 2 and 3.

Correct answer

A. Ratio of work functions ϕ1:ϕ2:ϕ3=1:2:4\phi_1: \phi_2: \phi_3=1: 2: 4.

Step-by-step solution

From the relation, eV=hcλ−ϕe V=\frac{h c}{\lambda}-\phi or V=V=\left(\frac{h c}{e}\right)(1λ)−ϕe\left(\frac{1}{\lambda}\right)-\frac{\phi}{e} This is equation of straight line. Slope is tan⁡θ=hce\tan \theta=\frac{h c}{e}ϕ1:ϕ2:ϕ3=hcλ01:hcλ02:hcλ03=1λ01:1λ02:1λ03=1:2:41λ01=0.001nm−1 or  λ01=10000A˚1λ02=0.002nm−1 or λ02=5000A˚1λ03=0.004nm−1 or λ03=25000A˚\begin{aligned} \phi_1: \phi_2: \phi_3 & =\frac{h c}{\lambda_{01}}: \frac{h c}{\lambda_{02}}: \frac{h c}{\lambda_{03}}=\frac{1}{\lambda_{01}}: \frac{1}{\lambda_{02}}: \frac{1}{\lambda_{03}}=1: 2: 4 \\ \frac{1}{\lambda_{01}} & =0.001 \mathrm{ nm}^{-1} \text{\text{ or } } \lambda_{01}=10000 Å \\ \frac{1}{\lambda_{02}} & =0.002 \mathrm{ nm}^{-1} \text{ or } \lambda_{02}=5000 Å \\ \frac{1}{\lambda_{03}} & =0.004 \mathrm{ nm}^{-1} \text{ or } \lambda_{03}=25000 Å \end{aligned}VioletcolourhaswavelengthViolet colour has wavelength4000 Å. So, violet colour can eject photoelectrons from metal-1 and metal-2.
Practice Dual Nature of Matter on Quantrex Academy →

More from Dual Nature of Matter

An electron and positron are accelerated from rest to the same kinetic energy. The ratio… MHT CET Medical 2026An electron of mass m and charge e initially at rest gets accelerated by a constant… MHT CET Medical 2026The wavelength λ_e of an electron and λ_P of a photon of same energy E are related as MHT CET Medical 2026A light of wavelength λ(λ < λ_0) falls on a metal surface. The momentum of the fastest… MHT CET Medical 2026The de Broglie wavelength of an electron with kinetic energy K_1 is λ_1 . If the kinetic… MHT CET Medical 2026A student plots two different graphs using the same photoelectric experiment data. 1.… MHT CET Medical 2026In a photoelectric cell, for the incident radiation of wavelength λ , the fastest… MHT CET Medical 2026A particle is dropped from a height ' y '. The de-Broglie wavelength of the particle as a… MHT CET Medical 2026 Full Dual Nature of Matter list All NEET PYQs