Physics Paper 3 Questions with Confidential - Kassu Jet Joint Mock Exams 2023

Instruction to Candidates

• You are supposed to spend the first 25 minutes of the 21/2 hours allowed for this paper reading the whole paper carefully before you start.
• Candidates ae advised to record their observations as soon as they are made.

QUESTIONS

Question 1 
You are provided with the following:

• A stirrer
• A stand, a boss and a clump
• A thermometer
• An ammeter
• A voltmeter
• A beaker
• A source of boiling water
• Two dry cells in a cell holder
• A switch
• Seven connecting wires
• A component labelled T

Proceed as follows:
 

1. Set up the circuit as shown in figure above.
   Close the switch, read and record the current I through component T and the potential difference V across it. (2mks)
   I =.......................... V =............................
   Open the switch.
   Determine the resistance R of component X given that: R =V/I (1mk)
2. Pour hot water into the beaker and set up the apparatus as in figure 2, so that component T and the thermometer bulb are fully immersed in the water.
   
3. Stir the water from time to time, when the temperature falls to 80°, switch on the circuit, read and record the current I and the potential difference V in table 1. Then open the switch.
4. Repeat (c) for every 5°C drop in temperature and fill the table below. Complete the table. (9mks)
   

   Temperature°c	80	75	70	65	60
   Temperature in Kelvin (K)
   Current, I(A)
   Potential Difference, V(V)
   Resistance,R=V/(Ω
   Log T
   Log R

5. On the axis provided, plot a graph of Log R against log T. (4mks)
   
6. Given that R and T are related by the equation Log R = Log Q + p Log T. determine the value of p and Q. (4mks)

Question 2
PART A
You are provided with the following apparatus

• A glass block (10 cm x 6 cm)
• A Plane mirror (7cm x 6 cm)
• 4 optical pins
• A soft board
• Cello-tape (about 15 cm long)
• 2 white – plain sheets of paper
• a vernier calipers
• A protractor
• 4 office pins
• Complete Mathematical set

Proceed as follows: - 

1. Using the cello tape provided fix the plane mirror to the glass block alongside as shown in the figure below. The reflecting surface to face the glass block.
   
   
2. With the use of the office pins, secure firmly a white plain paper on the board and place the block together with attached mirror.
3. Draw the outline of the glass block together with the mirror
4. Remove the block and the mirror and draw a normal at B somewhere a quarter- way the length of the outline you drew in (iii) above.
5. Draw four (4) different rays AB incident at B and extended to C. The incident rays should make incident angles of 10°, 20°, 30°and 40°.
6. Replace the glass block together with the attached mirror so as exactly fit the outline in(iii)
7. Place two optical pins P1 and P2 along the 10° line. Locate the images of pinsP1 and P2 as they appear by no-parallax method (the images of the pins appear to be in a straight line when viewed through the glass block). Place pins P3 and P4 so that the images of pins P1 and P2 are not seen.
8. Remove the glass block together with the attached mirror from the outline and produce the lines joining P1 to P2 and P3 to P4 so that the they intersect at C. Measure and record the distance d in the table below. (5mks)
   NB. It may be necessary for you to draw another outline so as to avoid congestion of (construction) lines.
   

   Angle i°	10	20	30	40
   Distance d (cm)
   Distance d (m)

9. Using a vernier calipers, measure the breadth b of the glass block.
   b=_________________________________________________cm (1mk)
   b= ______________________________________ m (1mk)
10. Calculate the average Ad of the values of d in the table above
    Ad _______________________________________ m (2mks)
11. Determine the refractive index of the glass block using the formula.
    Refractive index n of glass n=b/A_d (2mks)

PART B
You are provided with the following apparatus

• A triangular Card marked PQR
• A stand, a boss and a clamp
• 2 optical pins
• Stop watch
• Millimeter Scale
• Complete Mathematical set
  1. Draw the perpendicular line to the base QR and using a metre rule, measure and record, the height PM of the triangle.
     
     PM (h) = …………………………... cm (1mk)
  2. Using the optical pin provide make holes along the perpendicular line drawn such that the distance x = 1.0cm, 2.0cm and 3.0cm from P.
  3. By the other optical pin, hang freely the triangular card with the pin passing through the hole x=1.0cm. Displace the card so that it oscillates about the optical pin on its axis as shown below.
     
  4. Determine the time for 5 complete oscillations and record the values in the table below.
  5. Increase the distance x to 2.0 and repeat the experiment with x=3.0cm.
  6. Complete the table. (5mks)
     

     X(CM)	1.0	2.0	3.0
     Time for 5 Oscillations
     Periodic time, T(s)

  7. Determine the average value of Z. (2mks)

CONFIDENTIAL

Question 1
Each candidate is required to have:

• A stirrer
• A stand, a boss and a clamp
• A thermometer
• An ammeter (0 -1A)
• A voltmeter (0 -3V)
• A 250 ml beaker
• A source of boiling water
• 2 size D dry cells in a cell holder
• A switch
• Seven connecting wires
• A thermistor labelled T

Question 2
Each candidate is required to have:

• A glass block (10 cm x 6 cm)
• A Plane mirror (7cm x 6 cm)
• 4 optical pins
• A soft board
• Cellotape (about 15 cm long)
• 2 white – plain sheets of paper
• a vernier calipers
• A protractor
• 4 office pins
• A triangular Card marked PQR
• A stand, a boss and a clamp
• 2 optical pins
• Stop watch
• Millimeter Scale
• Complete Mathematical set