Two Polaroids P1 and P2 are placed with their axis perpendicular to each other. Unpolarized light Io is incident on P1. A third polaroid P, is kept in between P1 and P₂ such that its axis makes an angle 45° with that of P1. The intensity of transmitted light through P₂ is
A paper, with two marks having separation d, is held normal to the line of sight of an observer at a distance of 50m. The diameter of the eye-lens of the observer is 2 mm. Which of the following is the least value of d, so that the marks can be seen as separate? The mean wavelength of visible light may be taken as 5000 Å.
Interference was observed in interference chamber where air was present, now the chamber is evacuated, and if the same light is used, a careful observer will see
In a diffraction pattern due to a single slit of width 'a', the first minimum is observed at an angle 30° when light of wavelength 5000 Å is incident on the slit. The first secondary maximum is observed at an angle of:
The periodic waves of intensities I1 and I2 pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is:
The Young's double slit experiment is performed with blue and with green light of wavelengths 4360Å and 5460Å respectively. If x is the distance of 4th maxima from the central one, then
Angular width of the central maxima in the Fraunhofer diffraction for λ = 6000Å is When the same slit is illuminated by another monochromatic light, the angular width decreases by 30%. The wavelength of this light is
A parallel beam of fast-moving electrons is incident normally on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statements is correct?
