(a) What is a wavefront?

(b) (i) State two practical uses of glass prisms.

(ii) List two factors that determine the deviation of a ray of light travelling from air into a triangular glass prism.

(iii) Sketch a graph to illustrate the variation of the angle of deviation d, with that of incidence, i, for a ray of light travelling from air into a triangular glass prism. Indicate on the graph the point at which the angle of incidence equal to the angle of emergence e.

(c) (i) Draw and label a diagram of an astronomical telescope in normal adjustment.

(ii) The angular magnification of an astronomical telescope in normal adjustment is 5. If the focal length of the objective is 100cm, calculate the:

(\(\alpha\)) focal length of the eyepiece;

(\(\beta\)) length of the telescope.

To protect a material from the influnce of an external magnetic field, the materials should be kept

• A. square steel ring
• B. triangular zinc ring
• C. soft iron ring
• D. loop of copper wire

From the generating station to each substation power is transmitted at a very high voltage so as to reduce

• A. hysteresis loss
• B. eddy current loss
• C. magnetic flux leakage
• D. heating in the cells

A coin is pushed from the edge of a laboratory bench with a horizontal velocity of 15.0 ms^-1. If the height of the bench from the floor is 1.5m, calculate the distance from the foot of the bench to the point of impact with the floor [g = 10ms^-2]

• A. 0.75m
• B. 2.25m
• C. 8.22m
• D. 15.00m

An object is projected with a velocity of 80ms^-1 at an angle of 30^o to the horizontal.The maximum height reached is

• A. 20m
• B. 80m
• C. 160m
• D. 320m

A pipe open at both ends, produces a fundamental note. If the velocity of sound in air is V and L the length of the pipe, which of the following expresses the frequency of the note? Neglect end correction

• A. 2V/L
• B. V/2L
• C. V/3L
• D. V/4L

The distance between two successive trough of a wave is 0.4m. If the frequency of the source is 825Hz, Calculate the speed of the wave

• A. 165.0 ms^-1
• B. 330.0ms^-1
• C. 41.5ms^-1
• D. 85.0ms^-1

The thermopile is a device for detecting

• A. radioactive radiations
• B. radiant energy
• C. x-rays
• D. the presence of electrons

Which of the following statements is not an advantage of an alkaline accumulator?

• A. The electrolyte does not need attention
• B. It can be recharged
• C. It has low internal resistance
• D. It has a much longer life than lead-acid accumulator

The diagram below illustrates a block ans tackle pulley system in which an effort E supports a load of 100.0N. If the efficiency of the machine is 75%, calculate the value of E

• A. 22.2N
• B. 38.0N
• C. 67.0N
• D. 75.0N