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WorksheetsConvection
Total questions: 11
Worksheet time: 6mins
When air is heated, what happens to its mass?
increases
decreases
remains the same
When air is heated, its volume ____________.
increases
decreases
remains the same
When air is heated, its density ___________.
increases
decreases
remains the same
The diagram shows a refrigerator. The cooling unit is placed at the top. The cooling unit cools the air near it. What happens to the density of the air as it cools, and how does it move?
The density of air increases. It moves down.
The density of air increases. It moves up.
The density of air decreases. It moves down.
The density of air increases. It moves up.
The diagram shows some rice being boiled in a pan. What is the main methods by which thermal energy is transferred (i) through the metal pan and
(ii) through the water?
(i) conduction (ii) conduction
(i) convection (ii) convection
(i) conduction (ii) convection
(i) convection (ii) conduction
Convection can take place in ____________.
solids only.
liquids only.
liguids and gases only.
solids, liquids and gases.
Which of the following is an application of convection?
The movement of heat through a metal pan to the food.
The use of ice box to keep drinks cool.
The sea breeze that blows from sea to land.
The use of wool blanket to keep the body warm.
Which is the best position to place the heating element in an electric heater?
A
B
C
D
In the process of convection, energy is transferred _________.
because of temperature differences in a solid
because of density differences in a liquid
by the diffusion of molecules throughout a fluid
by the vibration of molecules
Which of the following correctly shows the direction of convection currents in water?
A
B
C
D
Some dye in a beaker of water is gently heated. Why are the streaks of dye seen in the water?
The hot dye is a better conductor than the cool water.
The hot dye is a better convector than the cool water.
The hot water is less dense than the cool water.
The hot water is denser than the cool water.
