Physics Paper 3 Questions - Mumias West Pre Mock Exams 2023

INSTRUCTIONS.

• Answer ALL the questions
• You are NOT allowed to start working with the apparatus for the first 15 minutes of the 2¼ hours allowed for this paper.
• This time is to enable you to read the question paper and make sure you have all the apparatus that you may need.
• Electronic calculators may be used
• All working must be clearly shown where necessary.

FOR EXAMINER’S USE ONLY.

QUESTIONS

Question 1

1. You are provided with the following.
   • A millammeter.
   • A voltmeter.
   • A wire mounted on a mm scale.
   • A switch.
   • A long wire with a crocodile clip at one and (crocodile clip to be used as a slider or jockey).
   • A new dry cell (size D) and a cell holder.
   • A micrometer screw gauge (may be shared).
   • 5 connecting wires, two with crocodile clips at the end.

Proceed as follows:

1. Measure the diameter, d of the mounted at three different points.
   
   Average diameter d = _____________________mm (1mk)
2. Set up the apparatus as shown in the circuit diagram in the figure below.
   
3. Close the switch and tap the mounted wire with the crocodile clip as shown in the circuit. Ensure that both meters show positive deflection. Open the switch.
4. Tap the wire at L = 20cm. Close the switch read and record in the time provided the milliammeter and voltmeter reading.
5. Repeat the procedure in (c) for other values of L, shown in the table below and complete the table. (8mks)
   

   L(cm)	L(m)	V (Volts)	I (mA)	I (Amps)	R =V / I
   20
   30
   40
   50
   60
   80

6.                  
   1. Plot the graph of R (Y-axis) against L(m). (5mks)
      
   2. Determine the slope of the graph. (3mks)
   3. Given that R = PL/A were A is the cross-sectional area of the wire and P is a constant for the material of the wire, determine the value of the constant P. (3mks)

QUESTION 2
PART A
You are provided with the following:

1. A white screen with crosswires
2. A Mounted lens
3. A White screen
4. A Candle
5. A Metre rule

Proceed as follows:
(f) Estimate the focal length of the lens by focusing the image of a distant object on the screen provided e.g. distant window.
f_o = ___________cm (1mark)

(g) Arrange the apparatus as shown.

With the object (cross-wires) illuminated using a candle flame placed at ? = 15??, move the screen until a sharp magnified image of the object is formed on the screen.
Measure and record the corresponding value of y in the table.

(h) Repeat step (g) for the value of ? = 18 ??
Table (3 marks)

(i) Determine the average of ? +? (2marks)
                                          ??
(j) Compare the average ? +? and 1 (2marks)
                                         ??         ?_?

(k) Given that 1 =      ?      ??? ? = 25 ??. ????????? ?ℎ? ????? ?? ?. (2marks)
                      ??    (^?/_?)+1
PART B
You are provided with the following:

• A watch glass
• A piece of plasticine
• A marble
• A Stopwatch
• An electronic balance (to be shared)
• Vernier calipers (to be shared)
• Geometrical set

Proceed as follows:

1. Measure the mass, m of the marble.
   m = …………………………g ( 1 mark)
2. Place the watch glass on the table. Cut the plasticine into two pieces and use them to hold the watch glass firmly on the table as shown in Figure 1.
3. Release the marble from one end of the watch glass and time 5 complete oscillation with the stopwatch. Repeat this one more time.
   
4. Record your values in the Table 1 (2 marks)
   

   Attempt	Time for 5 oscillations (seconds)	Periodic time, T(s)
   1st
   2nd

   Table 1
5. Find the average periodic time T (1 mark)
6.                
   1. Measure the diameter of the marble with the Vernier calipers, hence find its radius
      Diameter, d = ………………… (1 mark)
      Radius, r = …………………….m (1 mark)
   2. Determine the volume of the marble given that V= ⁴/₃πr³ where π=3.142 (2 marks)
   3. Calculate the radius of the curvature of the watch glass R from the formula R - r = 5??²
                                                                                                                                        7(2?)₂
      Where g=10m/s² and π=3.142 (2 marks)

CONFIDENTIAL

Question 1 

• A milliammeter(0-100 mA).
• A voltmeter(0-5V).
• A nichrome wire mounted on a mm scale. (diameter 0.22 mm) 
• A switch.
• A long wire with a crocodile clip at one and (crocodile clip to be used as a slider or jockey).
• A new dry cell (size D) and a cell holder.
• A micrometer screw gauge (may be shared).
• 5 connecting wires, two with crocodile clips at the end.

Question 2

• A white screen with crosswires
• A Mounted lens f=10±1 cm
• A White screen
• A Candle
• A Metre rule
• A watch glass
• A piece of plasticine
• A marble
• A Stopwatch
• An electronic balance (to be shared)
• Vernier calipers (to be shared)
• Geometrical set