Advertisements
Advertisements
प्रश्न
A ray of light travels a distance of 12.0 m in a transparent sheet in 60 ns. The refractive index of the sheet is ______.
विकल्प
1.33
1.50
1.65
1.75
उत्तर
A ray of light travels a distance of 12.0 m in a transparent sheet in 60 ns. The refractive index of the sheet is 1.50.
Explanation:
The refractive index can be calculated as,
`mu = c/v`
Where µ is the refractive index, c is the speed of light in air, `v` is the speed of light in the second medium.
Given: Distance d = 12 m, time t = 60 ns = 60 × 10-9 sec
`v = "distance"/"time"`
`v = (12/60) xx 10^9`
`v = (1/5) xx 10^9` m/s
`mu = (3 xx 10^8)/((1"/"5) xx 10^9)`
`mu = 3 xx 10^8 xx 5 xx 10^-9`
μ = 1.5
APPEARS IN
संबंधित प्रश्न
The speed of sound in air is 332 m s−1. Is it advisable to define the length 1 m as the distance travelled by sound in 1/332 s?
Consider Galileo's method of measuring the speed of light using two lanterns. To get an accuracy of about 10%, the time taken by the experimenter in closing or opening the shutter should be about one tenth of the time taken by the light in going from one experimenter to the other. Assume that it takes 1/100 second for an experimenter to close or open the shutter. How far should the two experimenters be to get a 10% accuracy? What are the difficulties in having this separation?
In Fizeau method of measuring the speed of light, the toothed wheel is placed in the focal plane of a converging lens. How would the experiment be affected if the wheel is slightly away from the focal plane?
The speed of light is 299, 792, 458 ms−1
(a) with respect to the earth
(b) with respect to the sun
(c) with respect to a train moving on the earth
(d) with respect to a spaceship going in outer space.
Which of the following methods can be used to measure the speed of light in laboratory?
In a Michelson experiment for measuring speed of light, the distance travelled by light between two reflections from the rotating mirror is 4.8 km. The rotating mirror has a shape of a regular octagon. At what minimum angular speed of the mirror (other than zero) the image is formed at the position where a nonrotating mirror forms it?
For light incident from air on a slab of refractive index 2, the maximum possible angle of refraction is ______.
A beam of light consisting of red, green and blue is incident on a right-angled prism as shown in figure. The refractive index of the material of the prism for the above red, green and blue colours are 1.39, 1.44 and 1.47 respectively. What are the colours suffer total internal reflection?
| A ray of light travels from a denser to a rarer medium. After refraction, it bends away from the normal. When we keep increasing the angle of incidence, the angle of refraction also increases till the refracted ray grazes along the interface of two media. The angle of incidence for which it happens is called critical angle. If the angle of incidence is increased further the ray will not emerge and it will be reflected back in the denser medium. This phenomenon is called total internal reflection of light. |
A point source of light is placed at the bottom of a tank filled with water, of refractive index µ, to a depth d. The area of the surface of water through which light from the source can emerge is:
A ray of light of wavelength 600 nm propagates from air into a medium. If its wavelength in the medium becomes 400 nm, the refractive index of the medium is ______.
