When the human eye loses its power of accommodation, the defect is known as

• A) short sightedness
• B) presbyobia
• C) astigmatism
• D) long sightedness

The ice and steam points on a mercury in glass thermometer are found to be 90mm apart. What temperature is recorded in degree Celsius when the length of the mercury thread is 33.6mm above the ice point mark?

• A. 33.6°C
• B. 35.0°C
• C. 37.3°C
• D. 52.7°C

(a) In an experiment to measure the specific latent heat of vapourisation of water, a student places a heater in a beaker containing water. The beaker stands on an electronic balance so that the mass of the beaker and water could be measured. The heater is switched on and readings were taken every 100s when the water starts boiling.

The table below shows the readings.

(I) Fill in the mass of water evaporated.

(ii) Given that the heater supplies energy at the rate of 38J/s, fill in the values of the energy supplied by the heater in 100s, 200s, 300s, and 400s.

(ii) Plot a graph of energy supplied on the vertical axis and mass of water evaporated on the horizontal axis, starting both axes from the origin(0,0).

(iv) Determine the slope of the graph.

(v) what does the value of the slope mean?

A hunter fires a gun at a point 408 m away from a cliff. If he hears an echo 2.4 s later, determine the speed of the sound wave

• A. 340 ms\(^{-1}\)
• B. 380 m s\(^{-1}\)
• C. 400 m s\(^{-1}\)
• D. 680 m s\(^{-1}\)

A ball is projected horizontally from the top of a tower. Neglecting air resistance, which of the following statements about its motion is/are correct?

I. Vertical acceleration on the ball decreases as it falls

II. The vertical force on the ball remains constant

III. The vertical speed of the ball increases as it falls

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

(a) What is electrolysis?

(b) A current of 2A is passed through a copper voltameter for 5 minutes. If the electrochemical equivalent of copper is 3.27 x 10\(^{-7}\) kg. Determine the mass of the corper deposited.

A wheel and axle is used to raise a load of 500 N by the application of an effort of 250 N. If the radii of the wheel and the axle are 0.4 cm and 0.1 cm respectively, the efficiency of the machine is

• A. 20 %
• B. 40 %
• C. 50 %
• D. 60 %

The frequency of a swinging pendulum is the

• A. number of complete oscillations the pendulum makes in a second
• B. number of amplitudes the bob makes in a second
• C. angle the bob swings through in a second
• D. distance the bob covers in a second

Flourescent tubes produces light by the

• A. excitation of gas molecules
• B. conduction of solar energy
• C. refraction of light by gas molecules
• D. thermal agitation of electron in the tubes

A ray of light passes from air to water to glass to air. Given that the refractive index for light passing from air to water is \(\frac{4}{3}\) and air to glass is \(\frac{3}{2}\), calculate the refractive index of glass relative to water

• A. 0.50
• B. 0.67
• C. 0.75
• D. 1.13