Radiation

The radiators on motor cars are painted black because ________.

• black surface is more beautiful

• a black surface can conduct heat better

• a black surface is a good radiator of infra-red rays

• it will not get dirtt easily

Tags

NGSS.MS-PS3-3

By which process is thermal energy transferred through a vacuum?

• conduction only

• convection only

• conduction and convection only

• radiation only

Which type of surface is the best absorber of infra-red rays?

• black and rough

• black and smooth

• white and rough

• white and smooth

Which type of surface is the best radiator of infra-red rays?

• black and rough

• black and smooth

• white and rough

• white and smooth

The diagram shows a simple form of solar water heater. Which tubing would give the hottest water from the outlet?

• black, plastic

• copper, painted black

• copper, painted white

• white plastic

A slice of bread is placed under a red-hot electric grill to make toast. What is/are the main process/processes by which the energy reach the bread?

• By conduction only.

• By conduction and convection

• By convection and radiation

• By radiation only

We feel the intense heat from the Sun when we stand in the open during noon time. How is heat transferred from the Sun to the Earth?

• By radiation only.

• By conduction and radiation only.

• By convection and radiation only.

• By conduction, convection and radiation.

A teapot is needed to keep tea hot for a long period of time. Which of the following best explains why teapots are usually made of a shiny metal?

• Shiny surfaces are good absorbers of infra-red radiation.

• Shiny surfaces are good emitters of infra-red radiation.

• Shiny surfaces are poor absorbers of infra-red radiation.

• Shiny surfaces are poor emitters of infra-red radiation.

Four different closed vessels contain equal amounts of ice.

Which vessel would take the shortest time for all the ice to melt?

• A

• B

• C

• D

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-3

NGSS.MS-PS3-4

A piece of aluminium foil is used to wrap around food to be cooked in an oven. The foil has a shiny side and a dull side. Which side should be on the outside and why?

• The dull side should be on the outside because it absorbs heat by radiation faster.

• The shiny side should be on the outside because it is a better conductor of heat.

• The dull side should be on the outside because it encourages convection current to be set up.

• The shiny side should be on the outside because it is a better absorber of heat by radiation.

Tags

NGSS.MS-PS3-5