A wire of cross-sectional area 2π * 10\(^-{8}\) m\(2\) and resistivity 1.1 x 10\(^-{8}\) Ω m, has a resistance of 21Ω.

Calculate the length of the wire. [π=22/7]

• A. 180 m
• B. 140 m
• C. 120 m
• D. 240 m

When a negatively charged rod is brought near the cap of a charged gold leaf electroscope which has positive charges, the leaf

• A. Remains the same
• B. Collapses
• C. Collapses and diverges again
• D. Diverges

(a)(i) State the law of inertia.

(ii) Use the law stated in (a)(I) to explain how wearing a safety belt in a moving vehicle could reduce the possibilities of severe injuries when the vehicle is involved in a collision.

(b)(I) Define the term moment of a force.

(ii) A uniform plank measures 2mlong from its ends point A to pointB. If the weight of the plank is 54Nand it rests on a knife edge 0.50mfrom endBand point A is supported by a vertical string so thatABbalances horizontally:

i. Draw a force diagram for the arrangement;

ii. Determine the tension,T, in the string.

iii. Determine the force,F, acting on the knife edge

(c) State three differences between solid friction and viscosity

(d) State one method of increasing the velocity ration of a pulley system.

Which of the following conditions occur at resonance in a series RLC circuit? i. Impedance equal resistance ii. Current is maximum iii. Reactance are maximum iv. Current and voltage are 90° out of phase

• A. i and ii only
• B. i and ii only
• C. i, ii and iii only
• D. i, ii, iii and iv

A body can undergo the following types of motion except

• A. random
• B. rotational
• C. translational
• D. relative

A certain radioactive source emits radiations that were found to be deflected by both magnetic and electric fields. The radiations are

• A. beta rays
• B. gamma rays
• C. x-rays
• D. ultrar-violet rays

When the pressure of the gas in a discharge tube is gradually lowered. I. there is a violet glow in the tube II. the glow in the tube splits into bands which get further apart. III, the glow and the bands eventually disappear and there is a green fluorescence in the tube. IV. the tube breaks into pieces. Which of the following are correct?

• A. I and II only
• B. I and III only
• C. I and IV only
• D. I, II and III only

Thermionic emission is the process whereby

• A) β - rays are produced
• B) holes are produced
• C) x - rays are produced
• D) electrons leave a hot element

An orange fruit drops to the ground from the top of a tree 45m tall. How long does it takes to reach the ground? (g = 10ms^-2)

• A. 3.0s
• B. 4.5s
• C. 6.0s
• D. 7.5s

In the microscope, the eyepiece lens merely acts as?

• A) an inverter
• B) a refiner
• C) a diminisher
• D) a magnifier