Maranda High KCSE Mock Exams Physics Paper 3

MARANDA HIGH SCHOOL

The Kenya Certificate of Secondary Education

MOCK EXAMINATION

232/3 Physics (Practical) Paper 3

Time: 2 Hours 15 Mins

Name: ………………………………………….…….…… Adm No: ………………

Stream: ……………………….. Signature: …………….

Instructions to Candidates

Write your name and index number in the spaces provided above.
Sign and write the date of examination in the spaces provided
Answer ALL the questions in the spaces provided in the question paper
You are supposed to spend the first 15 minutes of the 2 ½ hours allowed for this paper reading the whole paper carefully before commencing your work.
Marks are given for a clear record of the observations actually made.
Non-programmable silent electronic calculators and KNEC Mathematical tables may be used except where stated otherwise.

FOR EXAMINERS USE ONLY

QUESTION 1

	TOTAL
Maximum Score	20
Candidate’s Score

QUESTION 2

	TOTAL
Maximum score	20
Candidate’s score

TOTAL SCORE

QUESTION 1

You are provided with the following: –

2 new size D dry cells in a cell holder
A torch bulb in a bulb holder
A switch
An Ammeter
Seven connecting wires at least two with crocodile clips
A resistance wire PQ mounted on a mm scale
A micrometer screw gauge (to be shared)
A Voltmeter

Proceed as follows:

Set up the circuit as shown in the figure 1 .

Figure 1

With the crocodile clip at P, take the voltmeter reading and ammeter reading. Record V and I. Repeat the readings for L= 80, 60, 40, 20 and 0 cm respectively and complete table 1. (5 marks)

Table 1

Length, L (cm)	80	60	40	20	0
Voltage, V (V)
Current, I (A)

What changes do you observe on the bulb as L decreases from P? (1 mark)

………………………………………………………………………………………………………………………………………………………………………………………………

Plot a graph of Ammeter reading (y-axis) against Voltmeter readings. (4 marks)

Determine the slope of the graph at . (3 marks)

…………………………………………………………………………………………………………………………………………………………………………………………………….…………………………………………………………………………………………

What physical quantity is represented by the slope of the graph at any given point?

(1mark)

………………………………………………………………………………………………

Given the apparatus above, draw a diagram of the circuit you would use to determine the current through the resistant wire and the potential difference across. (2 marks)

Set up the circuit you have drawn. Record the ammeter reading and the voltmeter reading when

V = …………………………………….…….. (mark)

I = ……………………………………….. (mark)

Using a micrometer screw gauge, measure the diameter of the wire. (1 mark)

d = ……………………………………………m

Calculate the quantity and give its units, where . (2 marks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

QUESTION 2

PART A

You are provided with the following apparatus:

Metre rule
Thread
A complete retort stand
Two masses, a 50g and 20g mass
Water in a beaker
Liquid X in a beaker

Suspend the metre rule so that it balances at its centre of gravity G. Read and record the value of G.

…………………………………………………………………… (1 mark)

Suspend the 50g mass at a distance , then suspend the 20g mass and adjust its position such that the metre rule is balanced as shown in the figure 2

Figure 2

Record the distance distance

…………………………………………………. cm (1 mark)

While maintaining the distance , immerse the the 50g mass completely in water, as shown in the figure 3.

Figure 3

Adjust the position of the 20g mass to balance the metre rule again. Record the new distance

………………………………………………………….. cm (1 mark)

Using the results obtained above, calculate the value of , weight of the 50g mass in water.

(2 marks)

Determine the upthruston the 50g mass in water. (2 marks)

Repeat steps (d), (e) and (f) but now the 50g is totally immersed in liquid X as shown in the figure 4.

Figure 4

Using the results obtained above, calculate the value of , weight of the 50g mass in liquid X. (2 marks)

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

Determine the upthruston the 50g mass in liquid X. (2 marks)

Given that where . Calculate (2 marks)

QUESTION 2

PART B

You are provided with the following apparatus:-

A metre rule.
Stop watch.
Stand, clamp and boss.
Two pieces of wood.
A beam balance or electronic balance (to be shared)
Mass labelled M.

Proceed as follows:

Hang the spring vertically by clamping one end as shown in figure 5.

Figure 5

Measure the length, of the unloaded spring, and record below.

= ……………………………………………… cm (1 mark)

Hang the mass M given from the lower end of the spring. Measure the length, of the loaded spring.

= ………………………………….. cm (1 mark)

Find the value of

= ……………………………………..cm (1 mark)

Using the beam balance, determine the mass, M of the object.

M = …………………………………………kg (1 mark)

Hang the mass M from the lower end of the spring. Displace it by a small vertical distance and release so that the spring makes vertical oscillations. Measure and record, time for the number of oscillations given in the table 2.

Complete table 2. (3 marks)

Oscillations, N

Time in seconds, t (s)

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