(a) Define:

(i) reactance;

(ii) impedance in an a.c.

The diagram here illustrates an a.c. generator. When the coil is rotated, an e.m.f is induced in the coil.

(i) Explain why an e.m.f. is induced.

(ii) State the purpose of the slip-rings.

(iii) Name and state the law used to determine the direction of the induced current.

(iv) State two ways to increase the induced e.m.f.

(c) A lamp is rated 12 V. 6 W. Calculate the amount of energy transformed by the lamp in 5 minutes.

(a) Define binding energy in an atom.

(b) List three evidence to support the claim that X-rays are electromagnetic waves.

(c) List three peaceful uses of nuclear energy.

(d) Light of wavelength 4.5 x 10\(^{-7}\) in is incident on a metal resulting in the emission of photo electrons. If the work function of the metal is 3.0 x 10\(^{-9}\) J, calculate the:

(i) frequency of the incident light;

(ii) energy of the incident light;

(iii) energy of the photoelectrons. [Speed of light = 3.0 x 10\(^8\) ms\(^{-1}\), h = 6.6 x 10\(^{-34}\) Js]

You are provided with a pendulum bob, a metre rule, a stopwatch, a retort stand with clamp, and other necessary apparatus.
i. Suspend the pendulum bob from the clamp as illustrated in the diagram.

ii. Adjust the pendulum such that AC=L= 90 cm

iii. Displace the pendulum bob slightly such that it oscillates in a vertical plane.

iv. Measure and record the time t for 20 complete oscillations.

v. Evaluate T and \(\sqrt L\)

vi.Repeat the procedure for four others values of L= 80 cm,70 cm, 60 cm, and 50cm.

vii. Tabulate your readings

viii. Plot a graph with T on the vertical axis and \(\sqrt L\) on the horizontal axis.

ix. Determine the slope, s, of the graph.
x. Evaluate g= \(\frac{4\pi^{2}}{5^{2}}\) 

xi. State two precautions taken to ensure accurate results.

(b) i. Determine from your graph, the period of the pendulum for L= 75 cm.

ii. A simple pendulum bob is set into simple harmonic motion. Sketch a diagram of the setup and indicate on it; the positions of:
(a) maximum velocity.
(b) maximum acceleration of the bob

You are provided with a metre rule, lens, screen, ray box, and other necessary apparatus.

i. Set up the experiment as shown in the diagram above. Measure and record the diameter a\(_{0}\), of the illuminated object.

ii. Place the object at a distance x= 25cm from the lens. Adjust the screen until a sharp image is obtained on the screen.

iii. Measure and record the diameter, a, of the image.

iv. Measure and record the distance v between the lens and the screen.

v. Evaluate y = P = \(\frac{1+y^{2}}{y}\) and T= x+v.

vi. Repeat the procedure for x = 30cm, 35cm, 40cm and 45cm. In each case, determine the corresponding values of a,v,y, P and T.

vii. Tabulate your results.

viii. Plot a graph of P on the vertical axis against T on the horizontal axis starting both axes from the origin (0,0).

ix. Determine the slope, s, of the graph.

x. Determine the intercept, c, on the horizontal axis.

xi Evaluate K = \(\frac{c}{2}\)

xii. State two precautions taken to ensure accurate results.

(b)i.  Explain the statement, the focal length of a converging lens is 20cm.

ii. An object is placed at a distance x from a converging lens of focal length 20cm. If the magnification of the real image is 5, calculate the value of x.

You are provided with an ammeter, resistor, key, metre bridge, and other necessary apparatus.

i. Connect a circuit as shown in the diagram above.

ii. Close the key and use the jockey to make contact with AB at N such that AN = d = 25cm

iii. Read and record the ammeter reading.

iv. Evaluate 1\(^{-1}\).

v. Repeat the procedures for values of d = 35cmm, 50cm, 65cm and 80cm. In each case, record I and determine 1\(^{-1}\)

vi. Tabulate your results.

vii. Plot a graph with log on the vertical axis and d on the horizontal axis.

viii. Determine the slope, s of the graph.

ix. State two precautions taken to obtain accurate results.

(b)i. Use your graph to determine the value of d = l = 1.5A.

ii. State two factors that affect the resistance of a wire.