a) Define surface tension.
(b) State two methods by which the surface tension of a liquid can be reduced.
Explain why it is desirable to install an air conditioner near the ceiling of a room and not close to the floor.
(a) On what principle does lighting in a fluorescent tube operate?
(b) State two factors which determine the colour of light produced in a fluorescent tube.
The diagram above illustrates an arrangement of a cathode ray from an electron gun and a bar magnet placed perpendicularly to the direction of the ray. Will the ray bend downward or upward? Explain.
