Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETPhysicsDual Nature of Matter

A photosensitive metal with a threshold wavelength ₀ is illuminated separately by two monochromatic light sources, A and B. The properties of the sources are given below: Source Wavelength Intensity A 0.8 ₀ I B 1.2 ₀ 100 I If i_A and i_B are the respective photoelectric saturation currents produced by sources A and B, which of the following relationships is correct?

Options

  1. Ai_A > i_B
  2. Bi_B > i_A
  3. Ci_B = 100 i_A
  4. Di_A = i_B = 0

Correct answer

A. i_A > i_B

Step-by-step solution

For photoelectric emission to take place, the incident wavelength must be strictly less than the threshold wavelength ₀ ( For source A: The incident wavelength is _A = 0.8 ₀ . Since _A 0 ). For source B: The incident wavelength is _B = 1.2 ₀ . Since _B > ₀ , the energy of the incident photons is less than the work function of the metal. Therefore, no photoelectric emission takes place, and the current is zero ( i_B = 0 ), regardless of its high intensity. Comparing the two currents, we get i_A > i_B . Answer: i_A >

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 of their de Broglie wavelengths is 2026An electron of mass m and charge e initially at rest gets accelerated by a constant electric field E. The de-Broglie wavelength of the electron at time t is (h = Planck's constant) 2026The wavelength _e of an electron and _P of a photon of same energy E are related as 2026A light of wavelength ( < ₀) falls on a metal surface. The momentum of the fastest moving electron is p . In order to have the momentum of an electron equal to 2p , the required wa 2026The de Broglie wavelength of an electron with kinetic energy K₁ is ₁ . If the kinetic energy increases to 5K₁ , the new wavelength is ₂ = x ₁ . The value of x is 2026A student plots two different graphs using the same photoelectric experiment data. 1. Maximum kinetic energy ( K_ max ) against frequency ( ) 2. Stopping potential ( V_o ) against 2026In a photoelectric cell, for the incident radiation of wavelength , the fastest electron has speed 'v'. If the wavelength of incident radiation is changed to 3 , the speed of the f 2026A particle is dropped from a height ' y '. The de-Broglie wavelength of the particle as a function of height is 2026 Full Dual Nature of Matter list All NEET PYQs