Electricity — Science STD 10 — Question

The image formed by a spherical mirror is virtual. The mirror will be:

Light travelling from a denser medium to a rarer medium along a normal to the boundary:

The blue colour of sky is due to:

1. Refraction of light.
2. Dispersion of light.
3. Diffraction of light.
4. Scattering of light.

The axis of earth's magnetic field is inclined with the geographical axis at an angle of about:

A plotting compass is placed near the south pole of a bar magnet. The pointer of plotting compass will:

1. Point away form the south pole.
2. Point parallel to the south pole.
3. Point towards the south pole.
4. Point at right angles to the south pole.

Twinkling of stars is due to atmospheric:

1. Dispersion of light by water droplets.
2. Refraction of light by different layers of varying refractive indices.
3. Scattering of light by dust particles.
4. Internal reflection of light by clouds.

The person who is suffering from the following disease cannot donate eyes.

The speed of light in air is:

A boy records that 4000 joule of work is required to transfer 10 coulomb of charge between two points of a resistor of 50 Ω. The current passing through it is:

An electric generator converts:

1. Electrical energy into mechanical energy.
2. Mechanical energy into heat energy.
3. Electrical energy into chemical energy.
4. Mechanical energy into electrical energy.