K.C.S.E Physics Q & A - MODEL 2004PP2QN02

K.C.S.E Physics Q & A - MODEL 2004PP2QN02

​ a) In an experiment to determine the power of an electric heater, melting ice was place in a container with an outlet and the heater placed in the ice as shown in Fig. 2. The melted ice was collected.

​i) Other than the current and voltage, state the measurement that would be taken to determine the quantity of heat absorbed by the melted ice in unit time.
(ii) If the latent heat of fusion of ice is L, show how measurement in (i) above would be used in determining the power P. of the heater.
(iii) It is found that the power determined in this experiment is lower than the manufacturer‟s value indicated on the heater.
b) Fig 3 shows part of an experimental set up for estimating the diameter of an oil molecule.

i) Describe how the oil patch is formed
ii) In an experiment the diameter a, of the patch was measured to be 200mm for an oil drop of radius 0.25mm. Determine the diameter of the molecule of the oil.

answers