Physics

The tubos inside solar heating panels use the sun radiation to warm water

• Black surfaces absorb radiation well

• Black surfaces conduct heat well

• Black surfaces emit radiation well

• Black surfaces reflect radiation well

A copper rod heated at one end.

Which statement describes how heat transfer occurs in the copper?

• Energy copper molecules move from cooler end to hotter end.

• Energy copper molecules move from hotter end to cooler end.

• Energy free electrons move from cooler end to hotter end.

• Energy free electrons move from cooler end to hotter end.

Which statement about copper explains why it is a better conductor than glass/

• Atomic vibration is passed on to the neighboring copper atoms quickly

• there free electrons in copper

• there are density changes in copper

A solid bar is heated at one end, how is energy transferred to the other end of the bar?

• Heated molecules move along the bar, carrying energy to the other end

• Heated molecules move along the bar,giving energy to the others along the bar

• Heated molecules vibrate more rapidly and pass energy to other molecules.

A silver cup is filled with boiling water from a kettle.

A man touches the outside surface of the cup and finds that is extremely hot.Why is the surface hot?

• Convection takes place in boiling water

• Silver is a good conductor of heat

• The boiling water gives a latent heat

When the center of the beaker is heated, a convectional current is set up.What statement explains this?

• The evaporation of water causes water molecules to move up

• The expansion of water causes water molecules to move up

• The water above the heater rises because it becomes less dense

• The water at the sides sinks because it becomes less dense

By which process is heat conducted from the air to ice?

• conduction, convection, radiation

• conduction & convection only

• convection & radiation only

• conduction & radiation only

Two metal plates are painted, one matt (dull) and the other matt black.These are placed at equal distances from a radiant heater, the heater is turned on for 5 minutes.

Which plate absorbs more energy and which plate emits more energy at this time?

• emit: black absorbs: black

• emit: white absorbs: black

• emit:black absorbs:white

• emit: white absorbs: white

When cooking, how is heat transferred through an aluminium pan and through the handle?

• A

• B

• C

• D

Four containers are filled with water at the same temperature shown above.From which container does the water evaporate first?

• A

• B

• C

• D