Magnetic Effects of Electric Current — Science STD 10 — Question

In the reactor of a nuclear power plant, name the material which is used:
In the fuel rods.

What is the ratio of potential difference and current known as?

We know that light refracts (or bends) when it goes from one medium to another. Now, the atmosphere contains only air. Then how does light get refracted on passing through only air in the atmosphere?

A ray of light is incident normally on a plane mirror. What will be the:

1. Angle of incidence?
2. Angle of reflection?

Name the part of the eye:

Which changes the focal length of eye-lens.

What name is given to the ratio of sine of angle of incidence to the sine of angle of refraction?

A 1cm high object is placed at a distance of 2f from a convex lens. What is the height of the image formed?

If the refractive index for light going from air to diamond be 2.42, what will be the refractive index for light going from diamond to air?

Why does a ray of light bend when it travels from one medium into another?

What are the raw materials used for making biogas?