Thermal Equilibrium and Related Concepts

The video explains thermal equilibrium, where no net heat flow occurs between objects at the same temperature. It covers heat transfer between objects of different temperatures, the process of achieving thermal equilibrium, and its applications in ovens, refrigerators, and thermometers. The video also distinguishes between thermal energy and temperature, and discusses thermal properties and thermocouples.

What is thermal equilibrium?

• A state where there is a net flow of heat between two objects.

• A state where heat flows from a cooler object to a warmer object.

• A state where two objects in thermal contact have the same temperature.

• A state where two objects have different temperatures.

When two objects are in thermal contact, how does heat transfer occur?

• Heat transfers in both directions, but at different rates.

• Heat does not transfer between the objects.

• Heat transfers only from the cooler object to the warmer object.

• Heat transfers only from the warmer object to the cooler object.

What happens to the temperature of an object with higher temperature when it is in thermal contact with a cooler object?

• The temperature of the higher temperature object fluctuates.

• The temperature of the higher temperature object remains the same.

• The temperature of the higher temperature object decreases.

• The temperature of the higher temperature object increases.

What is the net heat flow when two objects reach thermal equilibrium?

• The net heat flow is infinite.

• The net heat flow is negative.

• The net heat flow is positive.

• The net heat flow is zero.

In an oven, when does thermal equilibrium occur?

• When there is no heat transfer between the oven and the food.

• When the temperature of the oven is higher than the food.

• When the temperature of the food is higher than the oven.

• When the temperature of the food equals the temperature of the oven.

Why does heat transfer from food to the air in a refrigerator?

• Because there is no thermal equilibrium.

• Because the food is colder than the air in the refrigerator.

• Because the food is warmer than the air in the refrigerator.

• Because the food and the air in the refrigerator are at the same temperature.

How does a thermometer measure body temperature?

• By being in thermal contact with the body until thermal equilibrium is reached.

• By being placed near the body without contact.

• By using a digital sensor that does not require contact.

• By measuring the air temperature around the body.

What is the unit of thermal energy?

• Watt

• Degree Celsius

• Joule

• Kelvin

What is the difference between thermal energy and temperature?

• Both are measures of hotness.

• Thermal energy is a measure of hotness, while temperature is a form of energy.

• Thermal energy is a form of energy, while temperature is a measure of hotness.

• Both are forms of energy.

What is a thermocouple?

• A device that heats objects by transferring heat.

• A device that measures temperature by being in thermal contact with an object.

• A device that generates EMF when there is a temperature difference between its ends.

• A device that cools objects by transferring heat.