The velocity of light in diamond, glass and water decreases in the following order:
water > glass > diamond
diamond > glass > water
diamond > water > glass
water > diamond > glass
Two sodium lamps are used in an interference experiment. The intensity produced by both lamps individually on the screen is I. The ratio of intensity of maxima to intensity of minima on the screen is
2:1
1:2
∞:1
1:1
Two points separated by a distance of 0.1 mm can just be inspected in a microscope when light of wavelength 6000 Å is used. If the light of wavelength 4800 Å is used, this limit of resolution will become
0.80 mm
0.12 mm
0.10 mm
0.08 mm
A mixture of light, consisting of wavelength 590 nm and an unknown wavelength, illuminates Young's double slit and gives rise to two overlapping interference patterns on the screen. The central maximum of both lights coincide. Further, it is observed that the third bright fringe of the unknown light. From this data, the wavelength of the unknown light is
393.4 nm
885.0 nm
442.5 nm
776.8 nm
The Young's double slit experiment is performed with blue and with green light of wavelengths 4360 Å and 5460 Å respectively. If x is the distance of the 4th maxima from the central one, then
x(blue) = x(green)
x(blue) > x(green)
x(blue) < x(green)
x(blue) / x(green) = 5460/4360
λa and λm are the wavelengths of a beam of light in air and in a medium respectively. If θ is the polarising angle, the correct relation between λa , λm and θ is
λa = λm tan2 θ
λm = λa tan2 θ
λa = λm cot θ
λm = λa cot θ
Two coherent light sources S1 and S2 (λ = 6000 Å) are 1 mm apart from each other. The screen is placed at a distance of 25 cm from the sources. The width of the fringes on the screen should be
0.015 cm
0.025 cm
0.010 cm
0.030 cm
In Young's double slit experiment, the seventh maximum with wavelength λ1 is at a distance d1 and the same maximum with wavelength λ2 is a distance d2. Then d1/d2
The resolution limit of the eye is 1. At a distance of x km from the eye, two persons stand with a lateral separation of 3 metres. For the two persons to be just resolved by the naked eye, x should be
10 km
15 km
20 km
30 km