Homework WB 18th March Conduction, Convection, Radiation

• Science
• Lower Secondary (Key Stage 3)

Homework WB 18th March

What is conduction?

1. The transfer of heat through sound waves.
2. The transfer of heat through radiation.
3. The transfer of heat through direct contact.
4. The transfer of heat through convection.

Which material is a good conductor of heat?

1. Metal
2. Plastic
3. Wood
4. Glass

What happens to the particles in a good conductor when heat is applied?

1. The particles expand and become lighter.
2. The particles vibrate and transfer heat energy.
3. The particles remain stationary.
4. The particles absorb the heat and become cold.

How does conduction differ from convection?

1. Conduction occurs in solids, while convection occurs in gases.
2. Convection requires a heat source, while conduction does not.
3. Conduction involves direct contact, while convection involves the movement of fluids.
4. Conduction is faster than convection.

What is an example of conduction?

1. Heat rising from a radiator.
2. Touching a hot pan and feeling the heat.
3. Air circulating in a room.
4. Steam rising from a boiling pot.

What is convection?

1. The transfer of heat through the movement of fluids.
2. The transfer of heat through direct contact.

Which of the following is an example of natural convection?

1. Boiling water in a pot.
2. Hot air rising from a heater.

How does convection differ from conduction?

1. Convection occurs only in solids.
2. Convection involves the movement of fluids, while conduction does not.

What role does convection play in the Earth's atmosphere?

1. It drives the movement of air masses and contributes to weather patterns.
2. It has no impact on atmospheric conditions.

What type of heat transfer occurs in a lava lamp?

1. Convection as the heated wax rises and cools, then sinks.
2. Radiation as the lamp emits light and heat.

Which method of heat transfer does not require a medium to travel through?

1. Radiation
2. Reflection
3. Conduction
4. Convection

In which method of heat transfer do particles carry heat energy from one place to another?

1. Radiation
2. Convection
3. Insulation
4. Conduction

Which method of heat transfer occurs through direct contact between particles?

1. Convection
2. Evaporation
3. Radiation
4. Conduction

What type of heat transfer involves the movement of electromagnetic waves?

1. Conduction
2. Radiation
3. Vibration
4. Convection

Which method of heat transfer is most effective in a vacuum?

1. Insulation
2. Radiation
3. Convection
4. Conduction

Insulation and r value

The R-value is a measure of how well a barrier, such as a layer of insulation, a window, a wall or ceiling, resists the flow of heat by conduction. The higher the R-value the better the performance. So the best insulators have the higher R values.

What is the purpose of insulation in a building?

1. To increase noise levels
2. To improve air quality
3. To attract pests
4. To regulate temperature and reduce energy consumption

Which material is a common form of insulation used in homes?

1. Fiberglass
2. Aluminum foil
3. Plastic wrap
4. Concrete

What is the R-value of insulation a measure of?

1. Its thermal resistance
2. Its color
3. Its flexibility
4. Its weight

What are the benefits of properly installed insulation?

1. Higher maintenance costs
2. Lower energy bills and increased comfort
3. Health hazards
4. Unpleasant odors

What is the recommended insulation for attics in cold climates?

1. Low R-value insulation like paper
2. High R-value insulation such as cellulose or spray foam
3. No insulation needed
4. Metal sheets