NAME: ……………………………….…………….INDEX NO: …………………CLASS...….
SCHOOL ………………… SIGNATURE: …………………DATE: ……………………
232 / 3
PHYSICS
PAPER 3
(PRACTICAL)
JUNE 2025
TIME: 2 ½ hours
EMUHAYA JOINT EVALUATION
(Kenya Certificate of Secondary Education (KCSE))
INSTRUCTIONS TO CANDIDATES
(a) Write your Name, Index Number and Admission number in the spaces provided above.
(b) Sign and write the date of Examination in the spaces provided above.
(c) Answer all questions in the spaces provided.
(d) You are supposed to spend the first 15 minutes of the 2½ hours allowed for this paper reading the whole paper
carefully before commencing your work.
(e) Marks will be given for clear records of observations actually made, their suitability, accuracy and the use made
of them.
(f) Candidates are advised to record their observations as soon as they are made.
(g) All working must be clearly shown where necessary.
(h) Mathematical tables and silent electronic calculators may be used.
(i) This paper consists of 8 printed pages. Candidates are advised to check that all pages are printed as indicated
and no questions are missing.
FOR EXAMINER’S USE ONLY
Question 1 a a b c c d e e g h TOTAL
i (ii) (i) (ii) i ii
Max. Score 1 3 5 2 2 2 1 1 2 1 20
Candidate’s
Score
Question 2 a b c g h j n TOTAL
Max. Score 2 3 5 2 3 1 4 20
Candidate’s
Score
GRAND TOTAL
1
QUESTION ONE
Instruction; attempt all question in both part A and B of this question.
PART A
You are provided with the following apparatus;
Two identical cylindrical 100g masses.
A metre rule.
Wooden block
A knife edge wooden block.
Four pieces of thread about 50cm in length.
A plastic beaker 250ml with a liquid approximately 200ml. labelled Liquid L.
A piece of cellotape about 20cm long.
10 microscope slides
A pair of vernier calipers(To be shared).
Procedure
a)i) Determine the center of gravity G of the metre rule and record it.
G……………………………………………… (1 mark)
ii) Arrange the apparatus as shown in the diagram below such that X=50mm from the pivot with 100g mass
completely immersed in liquid L hung the other 100g mass from the metre rule and adjust its position until the
system is in equilibrium as shown in figure 1 below. Record the value of Y when the system is in equilibrium in
the table 1.
Repeat the procedure above with the following values of X and fill the table for the values of Y
NB: During each experiment, ensure that the position of the pivot does not change.
X (mm) 50 100 150 200 240 300
Y (mm)
2
Tab. 1 (3 marks)
b) Plot a graph of Y (vertical axis) against X. (5 Marks)
c) From the graph determine;
(i) the slope S of the graph. (2 Marks)
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F
(ii) The value of F given that the slope S is given by the equation S= where W is the actual Weight of the mass in
W
liquid L . (2 Marks)
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PART B
You are provided with the following apparatus;
10 microscope slides
A piece of cellotape
A pair of vernier calipers
Two pieces of thread
Procedure;
d) Using the vernier calipers provided, measure the length, L, and the width , W, of one microscope slide.
(2 mark )
e) (i) Stack 10 slides together using a cellotape. See figure. 3 below
Measure the thickness T of the stack of the microscope slides. (1mark)
T=………………………………………….
(ii) Determine the volume ,V, of the stack of the microscope slide given that, V=LWT (1 mark)
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f) Balance the metre rule at its centre of gravity, G, on the knife edge and maintain this position throught the
experiment. Place one of the 100g mass and the stack of slides as shown in figure 4 below
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Adjust the position of both the stack and the mass until the rule is again balanced.
NB: make the distances X and Y as large as possible.
g) Calculate the mass m in grams of the stack of slides given that; (2 marks)
X
m=100
Y
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h) Determine the density of glass given that; (1 mark)
m
Density=
v
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2 A. You are provided with the following apparatus,
A voltmeter
An ammeter
A resistance wire labeled W
A wire mounted on a mm scale and labeled T
A micrometer screw gauge (to be shared)
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Six connecting wire with crocodile clips
Proceed as follows:
a) Using the micrometer screw gauge provided measure the diameter of the wire labeled T
d …………………………………………………………………. mm (1mk)
Determine the radius r of the wire
r = …………………………… m (1mk)
b) Set up the apparatus as shown below
V
W
i) Record the voltmeter (V) and ammeter (I) readings
V ………………………………………. V (1mk)
I ……………………………………….. A (1mk)
ii) Determine the resistance Rw of the wire W (1mk)
c) Set up your apparatus as shown below
VV
W
T
i) Use the voltmeter provided to measure the p.d Vw across W and VT across T when the switch is
closed.
Vw = …………………………………………. V (1mk)
VT = …………………………………………. V (1mk)
Open the switch.
ii) Use the value of Rw calculated in b (ii) and the value of Vw to calculate the current I flowing
through W when the switch was closed.
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I = …………………………….. (1 mk)
iii) Determine the constant K and its units given that,
(2mk)
RW . I
K=
VT
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You are provided with the following.
- A lens and lens holder.
- A candle.
- A screen.
- A metre rule.
Proceed as follows:
Set up the apparatus as shown in figure 2.
(f) Starting with U = 30cm, adjust the position of the screen to obtain a sharp image of
the candle. Record the value of V in Table 2.
(g) Repeat the procedure in (f) for U = 40cm. Complete the table.
U(cm) V(cm) V
m=
U
30
40 (2 marks)
Table 2
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V
f=
(h) Given that the focal length of the lens satisfies the equation 1 + m determine the
average value of focal length f. (3 marks)
…………………………………………………………………………………………………
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You are provided with the following :
- a glass block
- a plain sheet of paper
- five optical pins
- a half metre rule
Proceed as follows :
j) Measure the length, l, of the glass block.
l = ...................................................... cm (1 mark)
k) Place the glass block on the plain sheet of paper and trace its outline.
l) Place a pin P1 firmly at the middle of one end of the glass block as shown in figure 2 below.
P3
P2
I
P1
P4
P5 X
m) With your eye at the opposite end of the block, place pins P 2 and P3 so that they are in line with
the image I of pin P1 as shown in figure 2. Similarly locate the image I using pins P4 and P5.
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n) Remove the glass block and produce P3P2 and P5P4 to their point of
interection. f) i) Measure the distance, X, shown in figure 2.
X = ..................................................cm (1 mark)
ii) Determine the constant k given that
k
l
(2 marks)
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iii)What does constant k represent ? (1 mark)
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