Light – Reflection and Refraction — Science STD 10 — Question

Two devices are connected between two points say A and B in parallel. The physical quantity that will remain the same between the two points is:

For finding the focal length of a convex lens by obtaining the image of a distant object, one should use as the object:

A strong bar magnet is placed vertically above a horizontal wooden board. The magnetic lines of force will be:

1. Only in horizontal plane around the magnet.
2. Only in vertical plane around the magnet.
3. In horizontal as well as in vertical planes around the magnet.
4. In all the planes around the magnet.

Even in absolutely clear water, a diver cannot see very clearly because.

Linear magnification produced by a convex lens can be:

1. Less than 1 or more than 1.
2. Less than 1 or equal to 1.
3. More than 1 or equal to 1.
4. Less than 1, equal to 1 or more than 1.

The unit for expressing electric power is:

Which of the following coloured light has the least speed in glass prism?

The unit of what is named oersted in honour of Hans Oersted:

Four students P, Q, R and S traced the path of a ray of light passing through a glass slab for an angle of incidence of 40° and measured the angle of refraction. The values as measured by them were 18°; 22°; 25° and 30° respectively. The student who has performed the experiment methodically is.

The device used for measuring potential difference is known as:

1. Potentiometer.
2. Ammeter.
3. Galvanometer.
4. Voltmeter.