Q244. Consider the following statements: 1. Steam at 100°C and boiling water at 100°C contain the same amount of heat. 2. Latent heat of fusion of ice is equal to the latent heat of vaporization of water. 3. In an air-conditioner, heat is extracted from the room air at the evaporator coils and is rejected out at the condenser coils. Which of these statements is/are correct?

In a pressure cooker, the temperature at which the food is cooked depends mainly upon which of the following? 1. Area of the hole in the lid 2. Temperature of t

Which of the following is/are the example/examples of chemical change? 1. Crystallisation of sodium chloride 2. Melting of ice 3. Souring of milk Select the cor

The surface of a lake is frozen in severe winter, but the water at its bottom is still liquid. What is the reason?

Consider the following statements: 1. Molasses is a by-product of the sugar production process. 2. Bagasse obtained in the sugar mills is used as a fuel in the

Consider the following statements : 1. Jet streams occur in the Northern Hemisphere only. 2. Only some cyclones develop an eye. 3. The temperature inside the ey

What is the difference between a CFL and an LED lamp? 1. To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semiconductor material.

Consider the following statements: An ordinary light bulb has a rather short life because the: 1. filament wire is not uniform. 2. bulb cannot be evacuated comp

With reference to ‘fuel cells’ in which hydrogen-rich fuel and oxygen are used to generate electricity, consider the following statements: 1. If pure hydrogen i

Consider the following statements: A person in a spaceship located half way between the earth and the sun will notice that the: (1) The sky is jet black. (2) st

A hollow sphere of radius R, a hollow cube of side R and a thin circular plate of radius R, made up of the same material, are all heated to 20°C above

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 th

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

When water is heated from 0°C to 10°C. Its volume:

Cloudy nights are warmer compared to clear cloudless nights, because clouds:

Strips of two metals A and B are firmly joined together as shown in the figure. On heating, A expands more than B does. If this jointed strip is heat

Low temperatures (cryogenics) find application in:

"Membrane Bioreactors" are often discussed in the context of: