Physics Paper 2 Marking Scheme
KCSE CLUSTER TESTS 25
Physics Paper 2
SECTION A (25 Marks)
2 marks
Hammering causes the dipoles to vibrate making them to be aligned with the earth’s magnetic field hence the magnetization.
2 marks
A change in temperature causes a change in the tension/ length of the wire which in turn causes a change in the frequency of vibration of the string/sound produced.
2 marks
3 marks
3 marks
i) A is positive and B negative
ii) C is Ammonium chloride jelly.
D is A mixture of carbon and manganese dioxide
3 marks
Reduce the area of overlap
Increase the distance of separation ‘d’
2 marks
When the switch is closed, the nails are attracted.
When the switch is opened the nail on the iron side drops first.
2 marks
2 marks
4 marks
SECTION B (55 Marks)
a)
b)
c)
)
d)
12 marks
a) Suspend the bars independently away from magnetic materials using the string and allow them to settle. The bar magnet will settle in a N- S direction in line with the earth’s magnetic field while the iron bar can rest facing in any direction.
b)
i) During magnetization using an electric current, the dipoles in the materials get aligned in one direction as the .current increases. After sometime, all dipoles align themselves and a further increase in the magnetizing current ceases to have an effect on the degree of magnetization hence magnetic saturation is achieved.
ii) Q is easier to magnetize compared to P since it achieves magnetic saturation with a lower current than P.
7 marks
a) The ratio of the charge stored by a capacitor to the voltage across the plates. C=Q/V
b)
i)
C i)
ii)
11 marks
a)
i)See graph paper
ii) M=v/u Or H/h=2 (Use student diagram)
b)
i)
ii)
c)
Used in optical fibres and prism periscopes
14 marks
a) It is that point on the principal axis from which rays parallel and close to the principal axis appear to diverge after refraction by the lens.
b)
c)
i) See graph
ii) Intercept on the V axis= focal length Reading =10cm
11 marks