Physics Past Questions and Answers

(a) Explain electrolysis
(b) Classify the following substances as electrolytes and non-electrolytes: Sugar solution: paraffin, suit solution and grape fruit juice.

(a) State Heisenberg's uncertainty principle.
(b) Mention two phenomena that can only be explained in terms of the particulate nature of light.

(a) State the conditions for the equilibrium of a rigid body acted upon by parallel forces
(b)(i) Describe an experiment, using the principle of moments, to determine the mass of a metre rule
(ii) State two precautions necessary to ensure accurate results.
(c) A bullet of mass 120g is fired horizontally into a fixed wooden block with a speed of 20ms\(^{-1}\). The bullet is brought to rest in the block in 0.1s by a constant resistance. Calculate the:
(i) magnitude of the resistance;
(ii) distance moved by the bullet in the wood.

(a) Explain (i) work: (ii) power
(b) Show that the efficiency E, the force ratio M.A. and the velocity ratio V.R. of a machine are related by the equation: E = M.A. x 100% V.R.
(c) An inclined plane of angle 15° is used raise a load of 4500N through a height of 2m. If the plane is 75% efficient calculate:
(i) velocity ratio of the plane;
(ii) work done on the load
(d) Explain Charles' law using the Kinetic theory of matter.

(a) State three properties of waves
(b)(i) Describe, with the aid of a labelled diagram, an experiment to show how the frequency of the note emitted by a vibrating string depends on the tension in the string
(ii) State two precautions necessary to ensure accurate results.
(c) Draw a ray diagram showing how a virtual image of an object is formed by a concave mirror.