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NEETPhysicsDual Nature of Matter

Two monochromatic light sources, A and B, emit photons at the exact same rate. If the ratio of the power delivered by source A to that of source B is 3 : 4 , what is the ratio of their respective wavelengths, _A : _B ?

Options

  1. A3 : 4
  2. B9 : 16
  3. C16 : 9
  4. D4 : 3

Correct answer

D. 4 : 3

Step-by-step solution

The power P delivered by a light source is given by P = n hc , where n is the number of photons emitted per second, h is Planck's constant, c is the speed of light, and is the wavelength. For source A: P_A = n_A hc _A For source B: P_B = n_B hc _B Since both sources emit photons at the same rate, n_A = n_B . Therefore, the power is inversely proportional to the wavelength: P 1 . The ratio of their wavelengths is _A _B = P_B P_A . Given that P_A P_B = 3 4 , we get _A _B = 4 3 . Answer: 4 : 3

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