An object is placed on the principal axis at the centre of curvature of a concave mirror. The image of the object formed by the mirror is

• A. real, inverted and magnified
• B. at the principal focus
• C. real and diminished
• D. at the centre of curvature

A wheel and an axle is used to raise a load whose weight is 800N when an effort of 250N is applied. If the radii of the wheel and axle are 800mm and 200mm respectively, the efficiency of the machine is

• A. 90%
• B. 80%
• C. 85%
• D. 87%

Absorption line spectra exhibited by atoms is a result of

• A. change in the kinetic energy of a movimg atom
• B. instability of the nucleons
• C. excitation of an electron in the atom
• D. transition of an electron from a higher to a lower energy level

Two divers G and H are at depths 20m and 40m, respectively below the water surface in a lake. The pressure on G is p while the pressure on H is P, If the atmospheric pressure is equivalent to 10m of water, then the value of P/P is?

• A. 0.50
• B. 0.60
• C. 1.67
• D. 2.00

The value of T in the figure below is

• A. 10.0N
• B. 11.8N
• C. 20.0N
• D. 40.0N

A liquid of mass 1.0 x 10³kg fills a rectangular tank of length 2.5m and width 2.0m. If the tank is 4m high, what is the pressure at the middle of the tank?[g = 10ms^-2]

• A. 1.0 x 10⁴Nm^-2
• B. 2.0 x 10³Nm^-2
• C. 1.5 x 10³Nm^-2
• D. 1.0 x 10³Nm^-2

State three methods of polarising an unpolarised light

In an a.c circuit that contains only a capacitor, the voltage lags behind the current by

• A. 180°
• B. 90°
• C. 60°
• D. 30°

Calculate the current in the 30 resistor in the diagram below if the battery is of negligible internal resistance

• A. 0.3A
• B. 0.4A
• C. 1.0A
• D. 1.5A

I. change of state

II. Diffusion

III. Radiation

IV. Osmosis

Which of the processes above can be explained using the kinetic theory?

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