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

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): If an electron and a photon both have an energy of 50 eV, the linear momentum of the photon is greater than that of the electron. Reason (R): For a given energy E , the ratio of linear momentum of an electron to that of a photon is c 2m E , which is greater than 1 for E In the light of the above st

Options

  1. ABoth Assertion (A) and Reason (R) are true and (R) is the correct explanation of (A)
  2. BBoth Assertion (A) and Reason (R) are true but (R) is not the correct explanation of (A)
  3. CAssertion (A) is true but Reason (R) is false
  4. DAssertion (A) is false but Reason (R) is true

Correct answer

D. Assertion (A) is false but Reason (R) is true

Step-by-step solution

The linear momentum of an electron of energy E is p_e = 2mE . The linear momentum of a photon of energy E is p_ ph = E c . The ratio of their momenta is: p_e p_ ph = 2mE E c = c 2m E For the electron to have a greater momentum than the photon ( p_e > p_ ph ), the ratio must be greater than 1 : c 2m E > 1 2mc^2 E > 1 E The rest mass energy of an electron ( mc^2 ) is approximately 0.51 MeV. For an energy of E = 50 eV, the condition E 2mc^2 is easily satisfied. Therefore, the ratio is much greater than 1 , meaning the

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