Speed of Light Physics - Speed of Light

The speed of light is 299,792,458m/s.

1. With respect to the earth.
2. With respect to the sun.
3. With respect to a train moving on the earth.
4. With respect to a spaceship going in outer space.

The speeds of red light and yellow light are exactly same:

1. In vacuum but not in air.
2. In air but not in vacuum.
3. In vacuum as well as in air.
4. Neither in vacuum nor in air.

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,

1. The image will be shifted simultaneously with the object.
2. The image will be shifted a little later than the object.
3. The image will be shifted a little earlier than the object.
4. The image will not shift.

Which of the following methods can be used to measure the speed of light in water?

1. Roemer method.
2. Fizeau method.
3. Focault method.
4. Michelson method.

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:

1. Increase.
2. Decrease.
3. Remain constant.
4. First increase and then decrease.

In a Michelson experiment for measuring speed of light, the distance travelled by light between two reflections from the rotating mirror is 4.8km. 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 non-rotating mirror forms it?

What is the advantage of using a polygonal mirror with larger number of faces in Michelson method of measuring the speed of light?

In the original Fizeau method, the light travelled 8.6km and then returned. What could be the difficulty if this distance is taken as 8.6m?

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?

In an experiment with Foucault's apparatus, the various distances used are as follows:
Distance between the rotating and the fixed mirror = 16m
Distance between the lens and the rotating mirror = 6m
Distance between the source and the lens = 2m
When the mirror is rotated at a speed of 356 revolutions per second, the image shifts by 0.7mm. Calculate the speed of light from these data.

In an experiment to measure the speed of light by Fizeau's apparatus, following data are used:
Distance between the mirrors = 12.0km,
Number of teeth in the wheel = 180.
Find the minimum angular speed of the wheel for which the image is not seen.