Which one of the following statements about heat is correct>
It passes from cold objects to hot objects.
It passes from hot objects to cold objects
The more the heat flow the higher the temperature.
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
Conduction
Convection
Radiation
Insulation
Which one of these describes a solid material that blocks the flow of heat.
Conduction
Convection
Radiation
Insulation
The Sun passes its heat to the Earth by:
Conduction
Convection
Radiation
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:
Conduction
Convection
Radiation
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:
the computer or the temperature probe has probably failed.
a reverse convection current has been set up to cool the bottom of the tube.
radiation only starts to occur at the boiling point of water.
that water is a very bad conductor of heat.
The best kind of heat sink for a transistor (an electronic component) consists of:
just a single flat piece of bare metal.
metal shaped into a set of fins, coloured black.
metal shaped into a set of fins, coloured silver.
plastic shaped into a set of fins, coloured black
On a hot humid day, large clouds may form due to:
radiation from the Sun.
conduction of heat through the air.
convection currents of air heated by the hot land.
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:
they have a low surface area to volume ratio, so they lose heat less quickly and stay warm more easily.
there are more food sources about.
there is stronger radiation from the Sun, so they warm up quicker
they have black skin so they can loose heat more quickly.