In Young’s double-slit experiment, the two slits act as coherent sources of equal amplitude A and wavelength λ. In another experiment with the same set up, the two slits are of equal amplitude A and wavelength λ but are incoherent. The ratio of the intensity of light at the mid-point of the screen in the first case to that in the second case is:
(1) 1 : 2
(2) 2 : 1
(3) 4 : 1
(4) 1 : 1
A monochromatic beam of light falls on the YDSE apparatus at some angle (say θ) as shown in the figure. A thin sheet of glass is inserted in front of the lower slit S2. The central bright fringe (path difference = 0) will be obtained:
(1) At O
(2) Above O
(3) Below O
(4) Anywhere depending on angle θ, the thickness of plate t and refractive index of glass μ
Two point sources X and Y emit waves of same frequency and speed but Y lags in phase behind X by 2πl radian. If there is a maximum in direction D the distance XO using n as an integer is given by
(1)
(2)
(3)
(4)
A beam with wavelength λ falls on a stack of partially reflecting planes with separation d. The angle θ that the beam should make with the planes so that the beams reflected from successive planes may interfere constructively is (where n =1, 2, ……)
(1)
(2)
(3)
(4)
Two coherent sources separated by distance \(d\) are radiating in a phase having wavelength \(\lambda.\) A detector moves in a big circle around the two sources in the plane of the two sources. The angular position of \(n=4\) interference maxima is given as:
1. \(\text{sin}^{-1}\left(\frac{n\lambda}{d}\right )\)
2. \(\text{cos}^{-1}\left(\frac{4\lambda}{d}\right)\)
3. \(\text{tan}^{-1}\left(\frac{d}{4\lambda}\right)\)
4. \(\text{cos}^{-1}\left(\frac{\lambda}{4d}\right)\)
In a single slit diffraction of light of wavelength λ by a slit of width e, the size of the central maximum on a screen at a distance b is
(1)
(2)
(3)
(4)
The ratio of intensities of consecutive maxima in the diffraction pattern due to a single slit is
(1) 1 : 4 : 9
(2) 1 : 2 : 3
(3)
(4)
A wave is propagating in a medium of electric dielectric constant 2 and relative magnetic permeability 50. The wave impedance of such a medium is
(1) 5 Ω
(2) 376.6 Ω
(3) 1883 Ω
(4) 3776 Ω
A plane electromagnetic wave of wave intensity 6 W/m2 strikes a small mirror area 40 cm2, held perpendicular to the approaching wave. The momentum transferred by the wave to the mirror each second will be
(1)
(2)
(3)
(4)
In Young's double-slit experiment, the intensity at a point is (1/4) of the maximum intensity. The angular position of this point is:
(1) sin-1(λ/d)
(2) sin-1(λ/2d)
(3) sin-1(λ/3d)
(4) sin-1(λ/4d)