Prelims

Who is the scientist in whose honour the “Chandra” X-ray telescope has been named ?

Consider the following statements : In a nuclear reactor, self-sustained chain reaction is possible, because I. more neutrons are released in each of the fission reactions. II. the neutrons immediately take part in the fission process. III. the fast neutrons are slowed down by Graphite. IV. every neutron realeased in the fission reaction initiates further fission. Which of these statements are correct ?

When water is heated from 0°C to 10°C, its volume

Assertion (A): A piece of copper and a piece of glass are heated to the same temperature. When touched, thereafter, the copper piece appears hotter than the glass piece. Reason (R): The density of copper is more than that of glass.

Assertion (A): The boiling point of water decreases as the altitude increases. Reason (R): The atmospheric pressure increases with altitude.

When lightwaves pass from air to glass, the variables affected are

Two wires have their lengths, diameters and resistivities, all in the ratio of 1 : 2. If the resistance of the thinner wire is 10 ohms, the resistance of the thicker wire is

Assertion (A): A stick is dipped in water in a slanting position. If observed sideways, the stick appears short and bent at the surface of water. Reason (R): The light coming from the stick undergoes scattering from water molecules giving the stick a short and bent appearance.

The earlier name of WTO was

A class of animals known as Marsupials is a characteristic feature of