Unit 3 - Week 6 Revision

When there is an electric current passing through a wire, the moving particles are

• electrons

• protons

• atoms

• ions

Which of the following is not a valid a conclusion about electric current in a conductor?

• Electric charges move because of an electric field throughout a circuit.

• The electric field is produced by a source of energy that moves charges.

• The electric field is established at near the speed of light in a circuit.

• Electric charges move very fast in response to the electric field.

Provide an example of a discrete charge carrier

Calculate the charge when 4x10²⁴ electrons move into a solution of silver chloride. Give your answer as a decimal.

Calculate the current when 20 C of charge passes a point in 1 minute 30 seconds. Give your answer to 3 decimal points. No unit required.

"The amount of thermal energy transfer (heat) required to raise the temperature of 1 kg of a substance by 1 °C" is the definition for what property?

Truc mixes 100mL of iced tea at 5 °C with 250mL of hot tea at 70 °C. Determine the final temperature of the boba tea. Give your answer to 1 d.p.

A sample of hydrogen gas is kept in a sealed container. The internal energy of the gas is increased by 800 J. If the net work done on the sample by the environment was 500J, how much heat energy was transferred between the gas and the environment?

• 1300 J absorbed

• 300 J absorbed

• 300 J dissipated

• 1300 J dissipated

A steam engine does 4000J of work, while giving off 1500J of waste energy. Calculate the efficiency of the engine. Give your answer to 1 d.p. as a percentage. Do not write the % symbol.

In the image, which of the heat engines shown are NOT possible?

• A

• B

• C

• D