WAEC Physics 2003 Past Questions

(a) State two objects each used in sports and warfare which may be considered as projectiles. 

(b) the horizontal range R, of a projectile is given by the expression;

R = \(\frac{u^2 sin 2\theta}{g}\) where \(\theta\) is the angle of projection, g the acceleration of free fall due to gravity and u the initial velocity. At what value of \(\theta\) will R be maximium?

(a) What is surface tension?

(b) State two methods by which the surface tension of a liquid can be reduced.

(a) Explain diffusion

(b) State one factor that can affect the rate of diffusion.

(a) List two types of waves, apart from light, that can be plane polarized.

(b) State two applications of plane polarized light.

Explain the rise of water in a glass capillary tube using the kinetic theory.

(a) Explain the term electrolyte and give two examples.

(b) State the relationship between the mass of a substance liberated during electrolysis and the charge passed.

(a) What is the principle upon which the lighting in fluorescent tubes operate?

(b) State two factors which determine the colour of projection, g the acceleration of free fall due to gravity light from a fluorescent tube

Define;

(i) Elasticity

(ii) Young's modulus

(iii) Force constant

A force of 40 N applied at the end of a wire of length 4m and diameter 2.00 mm produces an extension of 0.24 mm. Calculate the;

(a) stress on the wire;

(b) strain in the wire (\(\pi = 3.142\))

(a) What is meant by the wave-particles duality of matter?

(b) mention one physical phenomenon, in each case, that can be explained in terms of the wave nature and particle nature of light.

(a) Define (i) Linear momentum; (ii) Impulse

(b) State the principle of conservation of linear momentum.

(c) A tractor of mass 5.0 x 10\(^{3}\)kg is used a tow a car of mass 2.5 x 103 kg. The tractor moved with a speed of 3.0 ms\(^{-1}\) just before the towing rope becomes taut. Calculate the:

(i) Speed of the tractor immediately the rope becomes taut

(ii) Loss in kinetic energy of the system just after the car has started Moving;

(iii) Impulse in the rope when it jerks the car into motion.

(a) Using the kinetic theory of matter, explain why; 

(i) Evaporation causes cooling

(ii) Boiling water changes to steam without any change in temperature, although heat is being supplied to the water.

(b) (i) State Boyle's law.

(ii) With the aid of a labelled diagram, describe an experiment to illustrate the relationship between the volume and pressure of a given mass of gas at constant temperature. (iii) State two precautions necessary to obtain accurate results.

a) (i) Illustrate, using a ray diagram, how an image can be formed by a convex mirror.

(ii) State one advantage rid one disadvantage of using a convex mirror as a iving mirror.

(iii) Explain the action of a compound microscope.

(b) Illustrate using labelled diagrams only, sonometer wire of length I, vibrating at its fundamental (ii) first overtone (iii) second overtone

(c) A tuning fork vibrating at a frequency of 512 Hz is held over the top of a jar filled with water and fitted with a tap at the buttom. If the jar is 60 cm tall and the speed of sound is 350 ms\(^{-1}\), determine the possible resonance position(s).

(a)(i) What is meant by neutral point in a magnetic field?

(ii) Draw and label a diagram to show the pattern and direction of the magnetic field produced around a straight current-carrying wire.

(b) When is an ammeter said to be (i) Sensitive (ii) accurate?

(c)(i) Explain, using a labelled diagram, how a delicate magnetic material could be protected, from the Earth's magnetic field.

(ii) A charge of 1.6 x 10\(^{-19}\) C enters a magnetic field of flux density 2.0 T with a velocity of 2.5 x 10\(^7\) ms\(^{-1}\) at an angle of 30° with the field. Calculate the magnitude of the force exerted on the charge by the field.

(d) State the laws of electro-magnetic induction.

(a)(i) Explain photoelectric emission.

(ii) State four applications of photoelectric emission.

(b) Draw and label a diagram showing the structure of a simple type of a photocell and explain its mode of operation.

(c) In a photocell, no electrons are emitted until the threshold frequency of light is reached.

(i) Explain what happens to the energy of the light before emission of electrons begin.

(ii) State one factor that may affect the number of emitted electrons.