What is thermal equilibrium?

Thermal equilibrium is the state when two or more objects in thermal contact have no net heat transfer between them because they are at the same temperature.

Why does net heat transfer stop between objects that have reached thermal equilibrium?

Because the objects are at the same temperature, so there is no temperature difference to drive heat flow.

If object A is in thermal equilibrium with object B, and object B is in thermal equilibrium with object C, what can be said about the temperatures of A and C?

Objects A and C are at the same temperature (and therefore in thermal equilibrium with each other).

Why is the thermodynamic temperature scale considered a fundamental scale?

Because it does not depend on the properties of any specific material or substance.

OCR A-Level Physics A H556

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Thermal Physics

Thermal equilibrium and absolute temperature

3 things to know
Papers 1, 2 and 3

Overview

Recall questions on thermal equilibrium, the absolute scale, and converting between kelvin and degrees Celsius.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Process

What is the SI unit of thermodynamic temperature?

Numbers

State the equation used to convert a temperature from degrees Celsius to kelvin.

Key term

What distinguishes the absolute (thermodynamic) temperature scale from other temperature scales?

Questions from this subtopic

Each one with the model answer underneath.

1
What is thermal equilibrium?
Model answer
Thermal equilibrium is the state when two or more objects in thermal contact have no net heat transfer between them because they are at the same temperature.
2
Why does net heat transfer stop between objects that have reached thermal equilibrium?
Model answer
Because the objects are at the same temperature, so there is no temperature difference to drive heat flow.
3
What can you conclude about the temperatures of two objects that are in thermal equilibrium with each other?
Model answer
Their temperatures are equal.
4
If object A is in thermal equilibrium with object B, and object B is in thermal equilibrium with object C, what can be said about the temperatures of A and C?
Model answer
Objects A and C are at the same temperature (and therefore in thermal equilibrium with each other).
5
What distinguishes the absolute (thermodynamic) temperature scale from other temperature scales?
Model answer
The absolute scale is independent of the properties of any particular substance.
6
Why is the thermodynamic temperature scale considered a fundamental scale?
Model answer
Because it does not depend on the properties of any specific material or substance.

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Thermal equilibrium and absolute temperature

Overview

What you need to know

What is the SI unit of thermodynamic temperature?

State the equation used to convert a temperature from degrees Celsius to kelvin.

What distinguishes the absolute (thermodynamic) temperature scale from other temperature scales?

Questions from this subtopic

What is thermal equilibrium?

Why does net heat transfer stop between objects that have reached thermal equilibrium?

What can you conclude about the temperatures of two objects that are in thermal equilibrium with each other?

If object A is in thermal equilibrium with object B, and object B is in thermal equilibrium with object C, what can be said about the temperatures of A and C?

What distinguishes the absolute (thermodynamic) temperature scale from other temperature scales?

Why is the thermodynamic temperature scale considered a fundamental scale?

Other ways to work this

What is inside Levo

The 3-step method, run for you

Cram a whole paper in one sitting

Blank Blitz makes facts automatic

Build It gets the exam shape right

Test It catches misconceptions

Brain Breaks between sessions

Every question in Thermal Physics, on a schedule.