(a) On which day would sound wave travel faster: on a hot or cold day? Explain.

(b) Why are megaphones shaped like funnels?

(c) A ray of light is incident on a surface of a ectangular glass prism of refractive index 1.5 illustrated in the diagram below.

(i) Copy the diagram a label the angles of: (\(\alpha\)) Incidence (x); (\(\beta\)) Reflection (y); (\(\gamma\)) refraction (z); with t glass letters indicated.

(ii) Calculate the angle refraction to the nearest whole number.

(d) A sonomesr wire vibrates in simple harmoi motion with a maximum amplitude of 1.0 cm. Calculate the frequency of vibration of the wire, giv that the magnitade of the maximum acceleration of the wire is 980ms\(^{-2}\). [\(\pi \frac{22}{7}\)]

(a) Explain briefly the purpose of earthing electrical appliance.

(b) Why does the light frorr bulb connected to a simple cell dim and eventually goes off after a while?

(c) A coil of incidence 0.007 H, a resistor of resistance 8 \(\Omega\) and a capacitor capacitance 0.001 F are connected in series an a.c. source of frequency \(\frac{500}{\pi}\)Hz. If the r.m.s voltages across the coil, the resistor and capacitor are 30v, 20v and 70v respectively;

(i) draw a vector diagram to illustrate the voltage across the components in the circuit.

(ii) Calculate the: (\(\alpha\)) r.m.s voltage of the source

(\(\beta\)) r.m.s current in the circuit;

(\(\gamma\)) power dissipated in the circuit.

iii) write down the sinusoidal equation for the r.m.s voltage, V, in terms of the time, t.

(a) Define ionization potential.

(b)(i) State the three types of emission spectra.

(ii) Name one source each which produces each of the spectra stated in (b)(i).

(c) In an x-ray tube, electrons are accelerated the target by a potential difference of 80 A Calculate the:

(i) speed of the electron;

ii) threshold wavelength of the electron. [h=6.6 x 10\(^{-34}\) Js; e = 1.6 x 10\(^{-19}\) C; Me = 9.1 x 10\(^{-31}\)

d) An x-ray photon of frequency 4.5 x 10\(^{-18}\) strikes an. electron, assumed to be at rest. If t electron absorbs all the photon energy, calculate the speed acquired by the electron. [ h = 6.6 x 10\(^{-34}\) Js; Me = 9.1 x 10\(^{-31}\) kg ]

(a) Define boiling point of a liquid.

(b) Describe how water in a round bottom flask could be made to boil without heating it. [diagram not necessary]

(c) State three applications of expansion of metals.

(d) A room with floor measurements 7m x 10 m contains air of mass 250 kg at a temperature of 34°C. The air is cooled until the temperature falls to 24°C. Calculate the: (i) height of the room;

(ii) quantity of energy extracted to cool the room;

(iii) which is higher: the calculated value or the actual energy needed to cool the room? Give a reason for your answer. [ Specific heat capacity of air = 1010 Jkg\(^{-1}\)K\(^{-1}\); density of air = 1.25 kg m\(^{-3}]

Name the three basic components P, Q and R that make up a cathode ray tube, as illustrated in the diagram above