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NEETPhysicsDual Nature of Matter

Photons of energy E are incident on two different photosensitive surfaces X and Y. The work functions of the surfaces are _X and _Y respectively, where _X < _Y < E . If _X and _Y are the minimum de Broglie wavelengths of the emitted photoelectrons from surfaces X and Y respectively, which of the following statements is correct regarding their relationship initially, and the effect on the ratio _X/ _Y if the incident

Options

  1. A_X < _Y , and the ratio _X/ _Y increases
  2. B_X > _Y , and the ratio _X/ _Y decreases
  3. C_X < _Y , and the ratio _X/ _Y decreases
  4. D_X = _Y , and the ratio _X/ _Y remains constant

Correct answer

A. _X < _Y , and the ratio _X/ _Y increases

Step-by-step solution

According to Einstein's photoelectric equation, the maximum kinetic energy of emitted photoelectrons is K = E - . Since _X K_Y . The minimum de Broglie wavelength of the photoelectrons is given by = h 2mK . Because K_X > K_Y , we have _X The ratio of the wavelengths is _X _Y = K_Y K_X = E - _Y E - _X . When the incident energy E is doubled to 2E , the new ratio becomes 2E - _Y 2E - _X . For any positive fraction where the numerator is less than the denominator, adding the same positive amount to both (or scaling E

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