Physics

1 cal = ?

• 4.2 J

• 1/ 4.2 J

• 1000 J

• 100 J

SI unit of heat is

• Calorie

• Celsius

• Joule

• Kelvin

Which thermometer is used to measure the temperature of a human body?

• Clinical thermometer

• Laboratory thermometer

• Digital thermometer

• both (a) and (c)

Cold water at a temperature of 5°C is mixed with hot water at 75°C. Then what will be the equilibrium temperature attained by the system?

• 30 °C

• 40 °C

• 50°C

• 70 °C

One litre of water at 30°C is mixed with one litre of water at 50°C.The temperature of the mixture will be

• more than 50°C but less than 80°C

• between 30°C and 50°C

• 80°C

• 20°C

An iron ball at 40°C is dropped in a mug containing water at 40°C. The heat will

• increase the temperature of both

• not flow from iron ball to water or from water to iron ball.

• flow from water to iron ball.

• flow from iron ball to water

Digital thermometer has a (a)   , which is used to sense the temperature.

1kcal = (a)   cal.

Expansion of a substance on heating depends on

• Nature of the substance

• Rise in temperature

• Color of the substance

• Both a and b

Heat loss may help the matter to

• Expand

• Spread

• Contract

• Stable