Instructions To The Candidates
- Answer all the questions in the spaces provided in the question paper.
- You are supposed to spend the first 15 minutes reading the whole paper carefully before commencing your work.
- Marks are given for clear record of the observations accurately made, their suitability and accuracy and the use made of them.
- Mathematical tables and electronic calculators may be used
Question 1
You are provided with the following;
- A piece of candle
- Plane mirror
- Metre rule
- A thin lens mounted on a lens holder
- A cardboard with cross-wire at its centre
- A piece of plasticine
- A white screen
Proceed as follows;
- Set up the apparatus as shown in figure 1.
Ensure that the candle frame is at the same height as the cross-wires. The plane mirror should also be attached to the lens as shown using a piece of cello tape. Plasticine can be used to fix the metre rule to the table. - Place the cardboard with cross-wire at the centre at the O mark of the metre rule.
- Move the object along the metre rule until a sharp image of the cross-wire is formed alongside the object cross-wire.
Measure the length d using the metre rule.
d: ………………………………………………………………m (2 marks) - Now arrange the candle flame, the lens the object and the screen as shown below.
- Adjust the distance between the lens and the object O to each of the distances given in the table. For every value of u, adjust the position of the screen until a sharp image of the cross-wires appears on the screen. Measure the value of v and record in the table.
- Repeat the procedure (e) above for each of the other values of u and complete the table below.
u (cm) 35 40 45 50 55 60 70 v (cm) uv(cm3) u + v (cm) -
- Plot the graph of uv against u + v. (5 marks)
- From your graph, calculate the slope, S (2 marks)
- Use the graph to determine the focal length. (2 marks)
- How is the focal length obtained in (i) above related to d obtained in c).
Explain your answer. (2 marks)
Question 2
PART I
You are provided with the following:
- A spiral spring
- One stand, one boss and one clamp
- A metre rule
- A stop watch
- A set of masses
Proceed as follows:
- Arrange the set-up as shown below
- Note the reading of the pointer of the spring when no mass is suspended from its hook.
Lo = _____________________ cm (1 mark) - Attach a 50g mass on the spiral spring and measure the length L of the spring with the mass 50g on the spring, slightly displace the spring downwards and note the time for 20 oscillations. Record your results in table 2 below
- Repeat procedure in c) above for 100g, 120g, 150g, 200g and 250g. Complete the table.
Table 2
Mass M(g) 50 100 120 150 200 250 L (cm) e = L – Lo (cm) time, t for 20 oscillations (s) Log t Log e - Plot the graph of log t against log e. (5 marks)
- Given that
Log t intercept = ½ log (16π²) Determine the value of A (2 marks)
A
PART II
You are provided with the following apparatus
- One new dry cell
- One cell holder
- Switch, K
- An ammeter
- A voltmeter
- A variable resistor, rheostat or potentiometer
- Seven connecting wires, at least 4 of which with crocodile clips
- A bulb holder
- A torch bulb 2.5V (for 2 dry cells)
- Set up the apparatus as shown below
- Set the ammeter reading to 0.04A, 0.06A and 0.08A using the rheostat. Get the corresponding readings and fill the table below. (3 marks)
Current (A) Voltage (V) Resistance (Ω) 0.04 0.06 0.08 - From the table, calculate the average resistance of the bulb filament. (1 mark)
CONFIDENTIAL
QUESTION 1
Provided the following apparatus
- One stand with the clamp and the boss
- One 100g mass
- 100cm long thread
- Two small pieces of wood. (0.5cm by 2cm by 5cm)
- Stop watch
QUESTION 2
Provided the following apparatus
- A wire mounted on a mm scale (0.35mm in diameter)
- A voltmeter (0-3 or 0- 5.v)
- An ammeter
- A switch
- Two dry cells and a cell holder.
- Six connecting wire with at least two crocodile clips.
- A micrometer screw gauge
MARKING SCHEME
Q1 (i) | d = 0.20 ± 0.01 m conversion to metre; accuracy | 1 mark 1 mark |
||||||||||||||||||||||||||||||||||||||||||
(f) |
|
5 mks 1mk 1mk |
||||||||||||||||||||||||||||||||||||||||||
g(i) |
2mks 1mk 1mk 1mk |
|||||||||||||||||||||||||||||||||||||||||||
Slope = 1600 – 0 ; 80 – 0 = 20cm; ± 2 |
1mk 1mk |
|||||||||||||||||||||||||||||||||||||||||||
Slope = Focal length; = 20cm; |
1 mk 1 mk |
|||||||||||||||||||||||||||||||||||||||||||
d is also the focal length; if the object is placed at the principal focus, the rays emerge parallel. The rays are then reflected by the plane mirror along the same path and hence the image is next to the object cross-wire; |
1mk 1mk |
|||||||||||||||||||||||||||||||||||||||||||
Q2(b) | Lo = 56.2cm (accept students value); | 1mk | ||||||||||||||||||||||||||||||||||||||||||
(d) |
|
1 mk 2 mks 3 mks |
||||||||||||||||||||||||||||||||||||||||||
1 mk 1mk 2mks 1mk |
||||||||||||||||||||||||||||||||||||||||||||
log t intercept = 0.67; 0.67 = ½ log (16π²) A log 4.677 = log (16π²) ½ A 16π²) ½ = 4.677 A A=7.219; |
1mk
1mk |
|||||||||||||||||||||||||||||||||||||||||||
(b) |
|
Readings 2mks Resistance 1mk |
||||||||||||||||||||||||||||||||||||||||||
(c) | Average resistance = 3.75 + 3.33 + 3.75 3 = 3.61Ω; |
1 mk | ||||||||||||||||||||||||||||||||||||||||||
GRAND TOTAL | 40 MKS |
Download Physics Paper 3 Questions and Answers - Pavement Pre-Mock Exams 2021/2022.
Tap Here to Download for 50/-
Get on WhatsApp for 50/-
Why download?
- ✔ To read offline at any time.
- ✔ To Print at your convenience
- ✔ Share Easily with Friends / Students