The energy stored in a simple cell is

• A. electrical
• B. nuclear
• C. thermal
• D. chemical

The mass and weight of a body on earth are 8kg and 80N respectively. Determine the mass and weight of the body respectively on a planet where the pull of gravity is \(\frac{1}{8}\) that on earth

• A. 8kg, 8N
• B. 1kg, 10N
• C. 64kg, 10N
• D. 8kg, 10N

(a) What is the principle upon which the lighting in fluorescent tubes operate?

(b) State two factors on which the colour of light from a fluorescent tube depends.

(a)(i) What is meant by the term artificial radioactivity?

(ii) Complete the table below

(b) In an x-ray tube, an electron is accelerated from rest towards a metal target by a 30 kV source. Calculate the kinetic energy of the electron. [e=1.6 x 10\(^{-19}\)C]

(c) The table below shows the frequencies of radiations incident on a certain metal and the corresponding kinetic energies of the photoelectrons.

(i) Plot a graph of kinetic energy, K.E, on the vertical axis and frequency, f, on the horizontal axis starting both axes from the origin (0,0).

(ii) From the graph, determine the:

i. Planck's constant;

ii. Threshold frequency of radiations;

iii. Work function of the metal.

A galvanometer of internal resistance 50Ω and full scale deflection of 20 mA is converted into a voltmeter by connecting a resistor of resistance 1950Ω in series to it. Calculate the maximum voltage that can be read by the voltmeter

• A. 20V
• B. 30V
• C. 38V
• D. 40V

The primary winding of a transformer has 400 turns and its secondary has 100 turns. If a source of e.m.f. of 12V is applied to the primary, the secondary e.m.f. will be

• A. 3V
• B. 6V
• C. 24V
• D. 48V

A radioactive substance has a half life of 20 days. What fraction of the original radioactive nuclei will remain after 80 days?

• A) 1/32
• B) 1/16
• C) 1/8
• D) 1/4

(a) Sketch a diagram of a simple pendulum performing simple harmonic motion and indicate positions of maximum potential energy and kinetic energy.

(b) A body moving with simple harmonic motion in a straight line has velocity, v and acceleration, a, when the instantaneous displacement, x in cm, from its maximum position is given by x = 2.5 sin 0.4 \(\pi t\), where t is in seconds. Determine the magnitude of the maximum (i) veloxity; (ii) acceleration

(c) A mass m attached to a light spiral is caused to perform simple harmonic motion of frequency

f = \(\frac{1}{2 \pi} \sqrt{\frac{k}{m}}\), where k is the force constant of the spring.

(i) Explain the physical significance of \(\sqrt{\frac{k}{m}}\).

(ii) If m = 0.30 kg, k = 30Nm\(^{-1}\) and the maximum position is 0.015m, calculate the maximum;

(i) kinetic energy

(ii) tension in the spring during the motion [g = 10 ms\(^{-1}\), \(\pi\) = 3.142]

(a) State two deductions that can be made from a displacement-time graph.

(b) If the distance beween two equal masses is doubled and their individual masses are also doubled, what would happen to the force between them? Support your answer quantitatively.

(c) State two factors that affect the maximum height attained by a bullet fired from a gun.

(d) State two practical examples of mechanical resonance. A body is released from rest at the top of a plane inclined at 30° to the horizontal and 4.0 m high. If the coefficient of friction between the body and the plane is 0.3, calculate the time the body takes to reach the bottom of the plane.

A train of mass 1600 kg attains a speed of 25 ms^-1 in 20 seconds. The power developed in the engine is?

• A. 2.5 KW
• B. 80 KW
• C. 25 KW
• D. 50 KW