(a) Distinguish between temperature and heat. State the units in which they are measured

(ii) State two physical properties used for measuring temperature.

(b) (i) Describe, with the aid of a diagram, how the upper fixed point is determined for a mecury-in-glass thermometer. State one precaution to ensure accurate results

(ii) State one advantage which a constant-volume gas thermometer has over other thermometers and one reason why it is seldom used as an everyday laboratory instrument.

(c) Using the kinetic theory of matter explain why evaporation causes cooling.

(a) Explain the terms reactance and impedance in an a.c circuit.

(b) A source of e.m.f. 240 v and frequency 50 Hz is connected to a resistor, an inductor and a capacitor in series. When the current in the capacitor is 10A, the potential difference across the resistor is 140V and that across the inductor is 50V. Draw the vector diagram of the potential difference across the inductor, the capacitor and the resistor. 
Calculate the (i) potential difference across the capacitor; (ii) capacitance of the capacitor; (iii) inductance of the inductor.

(a)(i) By means of a labelled diagram, describe the mode uf operation of a modern X-ray tube.

(ii) State the energy transformation which takes place during the operation.

(b) Explain the terms hardness and intensity as applied to X-rays

(c)(i) State three uses of X-rays

(ii) State one hazard of over-exposure to X-rays in a radiological laboratory, indicating two safety precautions.