Physics Past Questions and Answers

(a) State Faraday's law of electromagnetic induction.
(b) Draw a labelled diagram of an induction coil and explain how it works.
(c) How is the effect of eddy currents minimized in the coil?
(d) State two reasons why a capacitor should be included in the primary circuit of the coil.
(e) State three uses of an induction coil.

(a) What is surface tension? Explain the phenomenon in terms of intermolecular forces
(b) Describe a simple experiment to demonstrate the surface tension of a liquid
(c) State three examples to illustrate the effects of surface tension
(d) Why does water wet a clean glass surface whereas mercury does not?
(e) State two methods by which the surface tension of a liquid may reduced.

The diagram above represents a portion of a micrometer screw gauge in which the horizontal scale is in millimetres. What is the reading on the instrument?

The diagram above represents a portion of a micrometer screw gauge in which the horizontal scale is in millimetres. What is the reading on the instrument?

A loaded test-tube which floats upright in water is carefully and slightly depressed and then released. Which of the following best describes the sub-sequent motion of the test-tube?