PMS MCQs

Wood and many plastics conduct heat poorly.
They reduce heat transfer to the user's hand.

Metals transfer heat efficiently from the flame to food.
This makes cooking faster and more even.

Both spoons may have the same temperature.
Metal removes heat from the skin more quickly, creating a colder sensation.

Heating usually increases particle motion and separation.
This commonly causes thermal expansion.

Metal structures expand in hot weather.
Gaps prevent buckling and structural damage.

Melting occurs when a solid gains enough energy to become liquid.
It happens at the melting point under fixed pressure.

Freezing removes energy from a liquid until it forms a solid.
For pure water at standard pressure, this occurs at 0°C.

Evaporation occurs at the surface of a liquid.
Higher temperature and moving air usually increase its rate.

Condensation occurs when gas particles lose energy.
Water vapor condenses into droplets on a cool surface.

The highest-energy water molecules escape during evaporation.
This lowers the average energy and temperature of the skin.

Wind carries away water vapor near the fabric.
This maintains a concentration difference and speeds evaporation.

Convection occurs when warmer fluid moves and cooler fluid replaces it.
It happens in liquids and gases.