Which one of the following statements about heat is correct>

1.   ?    It passes from cold objects to hot objects.
2.   ?    It passes from hot objects to cold objects
3.   ?    The more the heat flow the higher the temperature.
4.   ?    Objects only radiate when they reach a temperature of at least 100 degrees Celsius

What do we call the process in which heat passes through a solid material

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

Which one of these describes a solid material that blocks the flow of heat.

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

The Sun passes its heat to the Earth by:

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

A small crystal of potassium permaganate (purple dye) is placed at the bottom of a beaker of water. The beaker is heated, and the purple dye is seen to rise. This is due to:

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

In an experiment, the top of a boiling tube of water is boiled. A temperature probe connected to a computer is at the bottom of the boiling tube. It registers hardly any change in temperature. The correct reason for this is:

1.   ?    the computer or the temperature probe has probably failed.
2.   ?    a reverse convection current has been set up to cool the bottom of the tube.
3.   ?    radiation only starts to occur at the boiling point of water.
4.   ?    that water is a very bad conductor of heat.

The best kind of heat sink for a transistor (an electronic component) consists of:

1.   ?    just a single flat piece of bare metal.
2.   ?    metal shaped into a set of fins, coloured black.
3.   ?    metal shaped into a set of fins, coloured silver.
4.   ?    plastic shaped into a set of fins, coloured black

On a hot humid day, large clouds may form due to:

1.   ?    radiation from the Sun.
2.   ?    conduction of heat through the air.
3.   ?    convection currents of air heated by the hot land.
4.   ?    difference in air pressure at ground level and high up.

Animals in cold regions tend to be bigger than animals in hot regions. The reason for this is that:

1.   ?    they have a low surface area to volume ratio, so they lose heat less quickly and stay warm more easily.
2.   ?    there are more food sources about.
3.   ?    there is stronger radiation from the Sun, so they warm up quicker
4.   ?    they have black skin so they can loose heat more quickly.

Heat radiation is called:

1.   ?    Ultra violet
2.   ?    Ultra red
3.   ?    Infra violet
4.   ?    Infra red