Human Eye and Colourful World — Science STD 10 — Question

Choose the correct option.
The magnetic field inside a long straight solenoid-carrying current,

When a ray of light travelling in glass enters into water obliquely:

Which of the following changes occur when you walk out of bright sunshine into a poorly lit room?

1. The pupil becomes larger.
2. The lens becomes thicker.
3. The ciliary muscle relaxes.
4. The pupil becomes smaller.

Which of the following is the most likely temperature of the filament of an electric light bulb when it is working on the normal 220V supply line?

1. 500°C
2. 1500°C
3. 2500°C
4. 4500°C

Though a woman can see the distant object clearly, she cannot see the nearby objects clearly. She is suffering from the defect of vision called:

The magnification produced by a spherical lens and a spherical mirror is +2.0.

1. The lens and mirror are both concave.
2. The lens and mirror are both convex.
3. The lens is convex but the mirror is concave.
4. The lens is concave but the mirror is convex.

If you are to determine to focal length of a convex lens, you should have

The 'coolants' which can be used in the reactor of a nuclear power station are:

1. Liquid mercury and nitrogen dioxide.
2. Liquid sodium and carbon dioxide.
3. Liquid ammonia and carbon monoxide.
4. Liquid boron and uranium oxide.