Photoelectric effect and dual nature questions with solutions

Showing 1–10 of 259 questions

• MCQeasyPhotoelectric effect and dual naturePhotoelectric Effect & Einstein's Equation

  A monochromatic source emits electromagnetic radiation with total power 15 kW at a rate of 2.5×10²² photons per second. Taking h = 6.6×10⁻³⁴ J·s and c = 3×10⁸ m·s⁻¹, in which region of the electromagnetic spectrum does the radiation lie?

  Options

  • Option A

    Microwave

  • Option B

    Infrared

  • Option C

    Visible

  • Option D

    Ultraviolet

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• MCQmediumPhotoelectric effect and dual naturePhotoelectric Effect & Einstein's Equation

  Incident radiation energy is increased by 20% and maximum kinetic energy rises from 0.5 eV to 0.8 eV. Find the metal work function.

  Options

  • Option A

    0.65 eV

  • Option B

    1.0 eV

  • Option C

    1.3 eV

  • Option D

    1.5 eV

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• MCQmediumPhotoelectric effect and dual naturePhotoelectric Effect & Einstein's Equation

  A photocathode of work function 1.5 eV is illuminated by a monochromatic source of fixed optical power. Initially the wavelength is 600 nm. It is then reduced to 300 nm, while the optical power and quantum efficiency remain unchanged. Which statement is correct?

  Options

  • Option A

    The saturation current doubles and the stopping potential decreases

  • Option B

    The saturation current halves and the stopping potential increases

  • Option C

    The saturation current remains unchanged and the stopping potential doubles

  • Option D

    The saturation current doubles and the stopping potential remains unchanged

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• MCQmediumPhotoelectric effect and dual natureDual Nature of Matter & de Broglie Wavelength

  Two identical non-relativistic particles move at right angles to each other and have de Broglie wavelengths λ₁ and λ₂. Find the de Broglie wavelength of each particle in the centre-of-mass frame.

  Options

  • Option A

    2λ₁λ₂/√(λ₁²+λ₂²)

  • Option B

    2λ₁λ₂/(λ₁²+λ₂²)

  • Option C

    √(λ₁²+λ₂²)/2

  • Option D

    λ₁λ₂/(λ₁+λ₂)

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• MCQmediumPhotoelectric effect and dual naturePhotoelectric Effect & Einstein's Equation

  Source S₁ emits 10¹⁵ photons/s of wavelength 5000 Å. S₂ emits 1.02 × 10¹⁵ photons/s of wavelength 5100 Å. The ratio of powers P₂/P₁ is:

  Options

  • Option A

    1.00

  • Option B

    1.02

  • Option C

    1.04

  • Option D

    0.98

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• MCQeasyPhotoelectric effect and dual naturePhotoelectric Effect & Einstein's Equation

  For the photoelectric effect, the maximum kinetic energy (Eₖ) of the photoelectrons is plotted against the frequency (ν) of the incident photons as shown in figure. The slope of the graph gives

  

  Options

  • Option A

    Ratio of Planck’s constant to electric charge

  • Option B

    Work function of the metal

  • Option C

    Charge of electron

  • Option D

    Planck’s constant

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• MCQeasyPhotoelectric effect and dual naturePhotoelectric Effect & Einstein's Equation

  Threshold frequency is 3.3 × 10¹⁴ Hz. Light of frequency 8.2 × 10¹⁴ Hz is incident. Cutoff voltage is nearest:

  Options

  • Option A

    2 V

  • Option B

    13 V

  • Option C

    5 V

  • Option D

    1 V

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• MCQmediumPhotoelectric effect and dual naturePhotoelectric Effect & Einstein's Equation

  Threshold wavelength for sodium photoelectric effect is 5000 Å. Its work function is approximately:

  Options

  • Option A

    4 × 10⁻¹⁹ J

  • Option B

    1 J

  • Option C

    2 × 10⁻¹⁹ J

  • Option D

    3 × 10⁻¹⁹ J

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  AIPMT 1988NEET Previous Year

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• NumericmediumPhotoelectric effect and dual naturePhotoelectric Effect & Einstein's Equation

  An isotropic monochromatic source emits 10 W of optical power at wavelength 400 nm. A small photocathode of area 2.0 cm² is placed 1.0 m from the source with its surface normal directed toward the source. The quantum efficiency is 20%. Take hc = 1240 eV·nm and e = 1.6×10⁻¹⁹ C. If the saturation current is approximately (N ÷ 10) μA, find N.

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• NumericmediumPhotoelectric effect and dual natureDual Nature of Matter & de Broglie Wavelength

  In one experiment, an electron is accelerated from rest through potential V₁, enters normally into a uniform magnetic field B, and moves in a circular path of radius r. In a second experiment, the magnetic field is increased to 3B and the electron is observed to move in a circular path of radius 2r. If the second accelerating voltage is V₂ = NV₁, find N.

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