Light travels in straight lines. In which of the following is this principle manifested? I. Pinhole camera II Formation of shadows III. Diffraction of light IV. Occurrence of eclipse

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

The horizontal component of the initial speed of a particle projected at 30° to the horizontal is 50 m\(^{-1}\). If the acceleration of free fall due to gravity is 10 ms\(^{-2}\), determine its;

(a) initial speed;

(b) speed at the maximum height reached.

It is observed that water will wet a clean glass because the

• A) cohesion of water to glass is stronger than the cohesion of water molecules
• B) adhesion of water molecules is weaker than the cohesion of water to glass
• C) cohesion of water to glass is weaker than the cohesion of water molecules
• D) adhesion of water molecules is stronger than the cohesion of water molecules

I. They should be identical

II. They should originate from the same source.

III. They should be coherent.

IV. They should be monochromatic.

From the statements above, the conditions for two waves to interfere are?

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

A body of mass 5kg movimg with a velocity of 30ms^-1 due east is suddenly hit by another body and changes its velocity to 50ms^-1 in the same direction. Calculate the magnitude of the impulse received.

• A. 100Ns
• B. 150Ns
• C. 250Ns
• D. 400Ns

(a) Explain what is meant by acceleration of free fall due to gravity, g.

(b) State two reasons why g varies on the surface of the earth

(c) A stone is projected upwards at an angle of 30° to the horizontal from the top of a tower of height 100 m and it hits the ground at a point Q. If the initial velocity of projection is 100ms\(^{-1}\), calculate the

(i) maximum height of the stone above the ground;

(ii) time it takes to reach this height;

(iii) time of flight

(iv) horizontal distance from the foot of the tower to the point Q. (Neglect air resistance and take g as 10m\(^{-2}\))

A motorist travelling at 72\(kmh^{-1}\) had his eyes shut for 0.4s during a hard sneeze. Calculate the distance covered by him during this time interval.

• A. 50.0m
• B. 28.8m
• C. 18.0m
• D. 8.0m

In Faradays law of electrolysis, a graph of the mass deposited against the quantity of electricity is plotted. The slope of the graph gives

• A) the energy released
• B) the electrochemical equivalent
• C) the current flowing
• D) the charge released

(a) (i) Explain why x-rays can be used to produce photographs of fractures in bones.

(ii) List four uses of x-rays other than in medicine.

(b) State the energy transformations which takes place during the operation of an x-ray tube.

(c) (i) Explain three named dangers to which human beings may be exposed when subjected to large doses of x-rays.

(ii) State two precautions that must be taken by persons working with x-rays.

(d) In an x-ray tube, an electron is accelerated from rest towards a tungsten target biased at a potential of 33 kV. Calculate, for the electron, the

(i) kinetic energy;

(ii) velocity. [h = 6.6 x 10\(^{-14}\) Js; Me = 9.1 x10\(^{-31}\) kg; c = 3.0 x 10\(^4\) ms\(^{-1}\); e = 1.6 x 10\(^{-19}\) C.]

The terminal voltage of a battery is 4.0V when supplying a current of 2.0A, and 2.0V when supplying a current of 3.0A. The internal resistance of the battery is

• A. 0.5Ω
• B. 1.0Ω
• C. 2.0Ω
• D. 4.0Ω