THERMAL EQUALIBRIUM

An earth-monitoring satellite falls into the earth’s atmosphere at a high velocity and reaches at the sea surface with a high temperature. After a while the temperature of the satellite is same as the temperature of the sea water. This is caused by

• The heat is released by the satellite

• The satellite is cooled by the sea water

• The satellite and the sea water are in thermal equilibrium

The diagram shows a metal sphere P at 80^oC is immersed in a cooler liquid Q. Thermal equilibrium is reached when

• temperature of P = temperature of Q

• mass of Q displaced = mass of P

• volume of Q = volume of P

• specific heat capacity of P = specific heat capacity of Q

The diagram shows two copper blocks, L and M, touching each other. The initial temperatures of L and M are 50 ^oC and 30 ^oC respectively. Which statement is correct when L and M are at thermal equilibrium?

• Temperature of L is higher than M

• The quantity of heat in L is the same as in M

• Rate of change in temperature of L is bigger than that of M

• Net rate of heat flow between L and M is zero

The diagram shows object A and object B are of temperatures T₁ and T₂. The heat flows from A to B until the thermal equilibrium is reached at a temperature T. Which relationship between T₁ , T₂ and T is true?

• T₁ > T₂ > T

• T₂ > T₁ > T

• T₁ > T > T₂

• T₂ > T > T₁

What is the concept used in the measurement of human body temperature using a thermometer?

• Specific heat capacity

• Specific latent heat

• Thermal equilibrium

• Thermal convection

6. Diagram shows a metal sphere at temperature of 90°C immersed in a liquid at temperature of 40°C.

What is the temperature of the metal sphere when thermal equilibrium is achieved between the sphere and the liquid?

• More than 90 °C

• Same as room temperature

• Less than 40 °C

• Between 40 °C and 90°C

Diagram shows hot water being added to cold water. Which of the following statements is correct if there are no heat losses to the surrounding?

• Heat lost by hot water is greater than heat gained by cold water.

• Heat lost by hot water is greater than heat gained by cold water.

• Heat lost by hot water is equal to heat gained by cold water.

What happens when the coffee and the cup are in thermal equilibrium?

• The temperature of the cup is increasing

• The temperature of the coffee is decreasing

• There is no net heat flow from the coffee to the cup

• There is a net flow from the coffee to the cup

6. The lengths of the mercury column in a thermometer at the ice point and the steam point are 5 cm and 25 cm respectively. When the thermometer is placed in a liquid , the length of the mercury column is 12 cm. What is the temperature of the liquid?

A 30 ^o C

B 35 ^o C

C 55 ^o C

D 70 ^o C

• 30 ^o C

• 35 ^o C

• 55 ^o C

• 70 ^o C

Diagram shows a spoon is placed in a bowl of soup at 95 °C. Which statement is correct when thermal equilibrium is reached?

• Temperature of soup is unchanged

• Temperature of spoon is unchanged

• No flow of heat between soup and spoon

• Soup and spoon has the same temperature