Convection

When air is heated, what happens to its mass?

• increases

• decreases

• remains the same

Tags

NGSS.MS-PS1-4

When air is heated, its density ___________.

• increases

• decreases

• remains the same

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

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.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

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

Tags

NGSS.MS-PS3-4

Convection can take place in ____________.

• solids only.

• liquids only.

• liguids and gases only.

• solids, liquids and gases.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

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.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-3

NGSS.MS-PS3-4

Which is the best position to place the heating element in an electric heater?

• A

• B

• C

• D

Tags

NGSS.MS-ETS1-1

NGSS.MS-ETS1-2

NGSS.MS-PS3-3

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

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Which of the following correctly shows the direction of convection currents in water?

• A

• B

• C

• D

Tags

NGSS.MS-ESS2-6

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.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4