Waec Physics Past Questions and Answers

Question 6:

• WAEC 2002

Explain the action of direct electric current in an electrolytic process with a dilute solution of sodium chloride as electrolyte

Question 7:

• WAEC 2002

(a) What is meant by;
(i) anode;
(ii) cathode, as used in electrolysis?
(b) List the ions involved in an electrolytic process with dilute tetraoxosulphate (VI) acid as electrolyte

Question 8:

• WAEC 2002

(a) Explain how neon signs can be produced.
(b) State two factors on which the colour of light from a fluorescent tube depend.

Question 9:

• WAEC 2002

Explain why a direct electric current is used instead of an alternating current in electroplating.

Question 10:

• WAEC 2002

(a) (i) What is meant by a machine?
(ii) List two examples of a simple machine.
(iii) Explain the statement – the velocity ratio of a machine is 5.
(b) (i) Define the efficiency of a machine.
(ii) Explain why a machine can never be 100% efficient.
(c) A screw jack, 25% efficient and having a screw of pitch 0.4 cm is used to raise a load through a certain height. If in the process, the handle turns through a circle of radius 40.0 cm, calculate the;
(i) velocity ratio of the machine; (ii) mechanical advantage of the machine; (iii) effort required to raise a load of 1000 N with the machine. [Take \(\pi\) =3.14]