Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETPhysicsWave Optics

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): When an unpolarised light beam is passed through a fixed polariser and then a continuously rotating analyser, the transmitted intensity becomes zero exactly twice during one complete 360^ rotation of the analyser. Reason (R): According to Malus's law, the transmitted intensity is proportional to th

Options

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

Correct answer

A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)

Step-by-step solution

Assertion (A) is true: As the analyser rotates through 360^ , the angle between the transmission axes of the polariser and the analyser changes from 0^ to 360^ . The transmitted intensity is zero when the axes are perpendicular (crossed polarisers), which occurs at = 90^ and = 270^ . Thus, the intensity becomes zero exactly twice in one complete rotation. Reason (R) is true: By Malus's law, the transmitted intensity is I = I₀ ^2 . The mathematical zeroes of in the interval [0^ , 360^ ) are at 90^ and 270^ , which d

Practice Wave Optics on Quantrex Academy →

More from Wave Optics

An unpolarized light beam of intensity I₀ passes through a series of n Polaroids P₁, P₂, P₃, P_n . The pass axis of each poloroid makes an angle of 60^ with the other poloroid. Wha 2026In a single-slit Fraunhofer diffraction experiment, the first secondary minimum is observed at an angle of 30^ for light of wavelength . If the same slit is now illuminated by ligh 2026In the Young's double slit experiment, the intensity of light at a point on the screen is 'K', being the wavelength of light used. The intensity at a point where path difference is 2026Two images are considered "just resolved" according to Rayleigh's criterion when 2026In Young's double slit experiment, the slits are 2 mm apart and are illuminated by photons of two wavelengths ₁ = 6000 Å and ₂ = 5000 Å one after the other. At what minimum distanc 2026In Young's double slit, 18 fringes are observed to be formed in a certain segment of the screen when light of wavelength 400 nm is used. If the wavelength is changed to 600 nm, the 2026When the un-polarised light beam is incident from air to glass (n = 1.5) at the Brewster's angle, 2026In Young's double-slit experiment, the intensity at a point is ( 1 4 ) of the maximum intensity. The angular position of this point is = wavelength of light used, d = separation be 2026 Full Wave Optics list All NEET PYQs