Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Concepts Of Physics MCQ Edition [Volume 2]PhysicsPhotoelectric Effect and Wave–Particle Duality

A sphere of radius 1.00 cm is positioned in the path of a parallel beam of light with a large aperture. The light has an intensity of 0.50 W cm ⁻² . Assuming the sphere completely absorbs the incident radiation, determine the force applied by the light beam on the sphere.

Options

  1. A1.0 10⁻⁸ N
  2. B2.1 10⁻⁸ N
  3. C1.7 10⁻⁹ N
  4. D5.2 10⁻⁹ N

Correct answer

D. 5.2 10⁻⁹ N

Step-by-step solution

The effective area of the sphere intercepting the parallel beam of light is its projected cross-sectional area, A = r^2 . Given r = 1.00 cm , the area is A = (1.00)^2 = cm ^2 . The total power absorbed by the sphere is P = I A . Substituting I = 0.50 W cm ⁻² , we get P = 0.50 = 0.50 W . Since the sphere completely absorbs the incident radiation, the force exerted by the light beam is the momentum transferred per unit time, F = P c . Using c = 3 10^8 m s ⁻¹ : F = 0.50 3 10^8 = 1.57 3 10^8 5.2 10⁻⁹ N

Practice Photoelectric Effect and Wave–Particle Duality on Quantrex Academy →

More from Photoelectric Effect and Wave–Particle Duality

Determine the net energy absorbed by an atom during a process in which it absorbs a photon of wavelength 500 nm and subsequently emits another photon of wavelength 700 nm .Compute the number of photons emitted per second by a 10 W sodium vapour lamp. Assume that 60 % of the consumed energy is converted into light. The wavelength of sodium light is 59Assuming the sun is directly overhead, the surface of the earth receives sunlight at 1.4 imes 10^3 W m ⁻² . Treat the light as monochromatic with an average wavelength of 500 nm , Assuming the sun is directly overhead, the surface of the earth receives sunlight at 1.4 10^3 W m ⁻² . Treat the light as monochromatic with an average wavelength of 500 nm , and aAssuming the sun is directly overhead, the surface of the earth receives sunlight at 1.4 10^3 W m ⁻² . Treat the light as monochromatic with an average wavelength of 500 nm , and aDetermine the momentum of a light photon that has a wavelength of 500 nm .Visible light encompasses wavelengths ranging from 400 nm to 780 nm . Determine the energy range of the photons of visible light.A beam of white light strikes a plane surface normally. The surface absorbs 70 % of the light while reflecting the remainder. Determine the force exerted on the surface by the beam Full Photoelectric Effect and Wave–Particle Duality list All Concepts Of Physics MCQ Edition [Volume 2] PYQs