Advertisements
Advertisements
Question
Which of the following methods can be used to measure the speed of light in laboratory?
Options
Roemer method
Fizeau method
Foucault method
Michelson method
Solution
Foucault method
Foucault gave the first laboratory method to find the velocity of light. He obtained a value of \[2 . 98 \times {10}^8 \text { m/s }\] from his measurements.
APPEARS IN
RELATED QUESTIONS
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?
In the original Fizeau method, the light travelled 8.6 km and then returned. What could be the difficulty if this distance is taken as 8.6 m?
What is the advantage of using a polygonal mirror with larger number of faces in Michelson method of measuring the speed of light?
Light passes through a closed cylindrical tube containing a gas. If the gas is gradually pumped out, the speed of light inside the tube will
An illuminated object is placed on the principal axis of a converging lens so that a real image is formed on the other side of the lens. If the object is shifted a little,
In an experiment with Foucault's apparatus, the various distances used are as follows:
Distance between the rotating and the fixed mirror = 16 m
Distance between the lens and the rotating mirror = 6 m,
Distance between the source and the lens = 2 m.
When the mirror is rotated at a speed of 356 revolutions per second, the image shifts by 0.7 mm. Calculate the speed of light from these data.
What is the speed of light in a denser medium of polarizing angle 30?
For light incident from air on a slab of refractive index 2, the maximum possible angle of refraction is ______.
If the velocity and wavelength of light in air is Va and λa and that in water is Va and λw, then the refractive index of water is ______.
When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as a plane sheet of glass. This implies that the liquid must have refractive index.
An air bubble in glass slab of refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness of the slab is,
Describe Fizeau’s method to determine the speed of light.
A small bulb is placed at the bottom of a tank containing water to a depth of 80 cm. What is the area of the surface of water through which light from the bulb can emerge out? Refractive index of water is 1.33. (Consider the bulb to be a point source.)
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 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. |
The critical angle of the pair of a medium and air is 30°. The speed of light in the medium is: