CBSE
Multiple Choice QuestionsIn young's double-slit experiment, the slits are 2 mm apart and are illuminated by photons of two wavelengths λ1 = 12000 A and λ2 =10000 A. At what minimum distance from the common central bright fringe on the screen 2 m from the slit will a bright fringe from one interference pattern coincide with a bright fringes from the other?
8 mm
6 mm
4 mm
4 mm
Which of the following is not due to total internal reflection ?
Difference between apparent and real depth of a pond
Mirage on hot summer days
Brilliance of diamond
Brilliance of diamond
Two slits in Young's experiment have widths in the ratio 1:25.The ratio of intensity at the maxima and minima in the interference pattern Imax/Imin is
9/4
121/49
49/121
49/121
On the first minimum adjacent to the central maximum of a single slit diffraction pattern, the phase difference between the Huygens wavelet from the edge of the slit and the wavelet from the midpoint of the slit is
π/4 radian
π/2 radian
π radian
π radian
The speed of light in media M1 and M2 is 1.5 x 108 m /s respectively. A ray of light enters from medium M1 and M2 at incidence angle i. If the ray suffers total internal reflection the value of i is
equal to sin-1 (2/3)
equal to or less than sin-1 (3/5)
equal to or greater than sin-1 (3/4)
equal to or greater than sin-1 (3/4)
Two periodic waves of intensities I2 and I2 pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is
I1 + I2
A boy is trying to start a fire by focusing sunlight on a piece of paper using an equal convex lens of focal length 10 cm. The diameter of the sun is 1.39 x 109 m and its mean distance from the earth is 1.5 x 1011 m. What is the diameter of the sun's image on the paper?
9.2 x 10-4 m
6.5 x 10-4 m
6.5 x 10-5 m
6.5 x 10-5 m
Two points are located at a distance of 10 m and 15 m from the source of oscillation. The period of oscillation is 0.05 s and the velocity of the wave is 300 m/s. What is the phase difference between the oscillation of two points?
π/3
2π/3
π
π
Two Polaroids P1 and P2 are placed with their axis perpendicular to each other. Unpolarised light I0 is incident on P1. A third polaroid P3
is kept in between P1 and P2 such that its axis makes an angle 45o with that of P1. The intensity of transmitted light through P2 is
I0/2
I0/3
I0/8
I0/8
Unpolarised light is incident from air on a plane surface of a material of refractive index 'µ'. At a particular angle of incidence 'i', it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation?
Reflected light is polarised with its electric vector parallel to the plane of incidence
Reflected light is polarised with its electric vector perpendicular to the plane of incidence
i = tan-1( 1/μ )
i = sin-1( 1/μ )
