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.

(a) Define electrolysis.

(b) Classify each of the following substances as an electrolyte or a non-electrolyte

(i) sugar solution;

(ii) kerosene;

(iii) alkaline solution

(iv) lemon fruit juice.

(a) State Heisenberg's Uncertainty Principle.

(b) State one phenomenon that can only be explained in terms of the wave nature of light.

(a) A particle moves on a straight path with an initial speed u and final speed v in time t. Show that the total distance X covered by the particle is given by

\(x = ut + \frac{1}{2}at^2\)

where a is the magnitude of acceleration

(b) State;

(i) Newton's second law of motion

(ii) the principle of conservation of energy

(iii) the law of floatation.

(c) Consider a balloon of mass 0.030 kg being inflated with a gas of density 0.54 kg m\(^{-3}\). What will be the volume of the balloon when it just begins to rise in air of density 1.29 kg m\(^{-3}\)? [ g = 10 ms\(^{-2}\)]

(a) State two differences between boiling and evaporation.

(b) A closed inexpansibie vessel contains air saturated with water vapour at 77°C. The total pressure in the vessel is 1007 mmHg. Calculate the new pressure in the vessel if the temperature is reduced 1.2 27°C. [ The s.v.p. of water at 77°C and 27°C respectively are 314 mmHg and 27 mmHg. Treat the air in the vessel as an ideal gas]

(c) The lengtn of a zinc rod at 23°C is 200 m. Calculate the increase in length of the rod when its temperature rises to 33°C. [ expansivity of zinc = 2.6 x 10\(^{-5}\) K\(^{-1}\)]

(d) Explain with there is no temperature change when a solid being heated changes into liquid at its melting point.