Physics Paper 3 Questions and Answers with confidential - Nginda Girls Mock Examination 2023

Instructions

• You are supposed to spend the first 15 minutes of the 2 1/2 hours allowed for this paper reading the whole paper carefully before commencing the work.
• Marks are given for a clear record of the observations actually made, their suitability, accuracy and the use made of them.
• Candidates are advised to record their observation as soon as they are made.
• Non programmable silent electronic calculators may be used.
• Candidates should answer the questions in English.

QUESTIONS

QUESTION 1 (20 marks)
You are provided with the following apparatus;

• Two dry cells (size D) and a cell holder
• A milliammeter (0 – 100 mA)
• A voltmeter (0 – 5 V)
• A resistor wire mounted on a millimeter scale labelled AB
• A diode (Anode labelled X)
• Jockey
• Eight connecting wires at least 6 with crocodile clips

Proceed as follows: 

1.  Set up the circuit as shown below.
   
   
2. Connect Jockey to L = 50cm mark. Record the value of current and its corresponding voltage.
   I ……………………………………………. (1mk)
   V…………………………………………… (1mk)
3. Now, connect the jockey to L = 0 cm, 10 cm, 20 cm, 30 cm… and fill the values of current and their corresponding values voltage in the table below. (8mks)
   

   L (cm)	0	10	20	30	40	50	60	70	80
   I (mA)
   V(v)

          

4. Plot graph of volume, I (y-axis) against V. (5mks)
   
5. From the graph, determine
   1. the slope at V = 0.65 V. (3mks)
   2. the resistance, R of the diode at V = 0.65 V in SI unit. (3mks)

QUESTION 2
PART A
You are provided with the following:

• Retort stand Geometrical set
• Four optical pins Thermometer
• A 100 ml plastic beaker Plain paper
• Soft board Stopwatch
• Source of boiling water Four thumb tucks
• Equilateral triangular glass prism
  Proceed as follows
  1. Fix the plain paper on the soft board using the office pins.
  2. On the plain paper, draw line XY. Mark a point M on its midpoint. Draw a normal N at M to XY. Draw line RM such that angle RMN = 50°.
     (This paper will be collected at the end of the experiment). (1mk)
     
  3. Place the glass prism such that one edge AB of the prism is in line with XY. Accurately draw the outline ABC of the prism
  4. Place optical pins P1 and P2 on the line RM
  5. Through edge BC observe the images of P1 and P2. Fix P3 and P4 so that P1, P2, P3 and P4 lie on straight line.
  6. Remove the pins; construct straight line from P4 through P3 to meet side BC at D, join M to D.
     1. Measure angle r1. (1mk)
        r1 = ………………………………..
     2. Produce P4P3 to meet RM produced. Measure angle d. (1mk)
        d………………………………..
     3. Draw the normal at D and measure the angle r2. (1mk)
        r2 ……………………………….
  7. Given that R= r1+ r2. Calculate R. (2mk)
  8. Given that n=sin⁡((R+d)/2)/sin⁡(R/2) , find the value of n. (3mks)
  9. Given that n sin⁡ k=1 , find the value of k. (2mks)
  10. What Physical property does n represent? (1mk)

PART B

11. Measure 100 ml of hot water and pour it into the beaker. Place the beaker on the bench. Clamp the thermometer vertically and insert it into the beaker with hot water.
    
    
12. Start the stop-watch when the temperature is 80°C. Record the temperature, θ after 4 minutes.
    θ = ………….°C. (1mk)
    Convert to θ in degrees Celsius to temperature T, in kelvin.
    T = ………………..K. (1mk)
    1. Find the mass, m (in kg) of water in the beaker given that the density of water is 1000kg/m³. (2mks)
13. Given that: γ=(mc(353-T))/240 where; m is the mass of the water used and the specific heat capacity of water, c = 4200J/kg/K, determine the value of γ. (3mks)
14. State the significance of γ. (1mks)

Confidential

QUESTION 1
You are provided with the following apparatus;

• Two dry cells (size D) and a cell holder
•  A milliammeter (0 – 100 mA)
• A voltmeter (0 – 5 V)
• A resistor wire mounted on a millimeter scale labelled AB
•  A diode with anode labelled x (preferrable 6A10 MIC or any other available)
• Jockey
• Eight connecting wires at least 6 with crocodile clips

QUESTION 2
Each student should have the following

• Four optical pins
• Plain paper (A4 size)
• Soft board
•  Four thumb tucks
• Equilateral triangular glass prism
• Complete geometrical set
• Thermometer
• Retort stand
• Access to hot water (above 85°C)
•  100 ml plastic beaker
•  Stop watch.

MARKING SCHEME

QUESTION 1

1. Set up the circuit as shown below.
   
2. Connect Jockey to L = 50cm mark. Record the value of current and its corresponding voltage.
   I ……………45 mA……………………… (atleast awhole number figure) (1mk)
   V………….. 0.9 v………………… (1dp a must) (1mk)
3. Now, connect the jockey to L = 0 cm, 10 cm, 20 cm, 30 cm… and fill the values of current and their corresponding values voltage in the table below. (8mks)
   

   L (cm)	0	10	20	30	40	50	60	70	80
   I (mA) ±5	0	0	0	7	24	45	64	78	96
   V(v) ±0.2	0	0.2	0.4	0.6	0.8	0.9	1.0	1.1	1.2

4. Plot graph of volume, I (y-axis) against V. (5mks)
5. From the graph, determine
   1. the slope at V = 0.65 V. (3mks)
      tangent on the curve at v = 0.65 V (Clearly drawn on graph = 1mk)
      S=(40-6)mA/((1.00-0.58)V) = (34)mA/(0.42)V (Correct substitution = 1mk)
      =80.95 mA⁄V
   2. the resistance, R of the diode at V = 0.65 V in SI unit. (3mks)
      From Ohm’s law,
      R=V/I ,therefore,R= 1/s
      R= 1/(80.95) (Correct substitution = 1mk)
      =0.01235 V⁄mA (Correct evaluation = 1mk)
      Hence,
      R=0.01235 x 1000 V⁄A
      =12.35 Ω (Correct evaluation = 1mk)

QUESTION 2

2. Outline sketch of the triangular glass prism with rays and relevant angles drawn (1mk)
   d)
   1. Measure angle r1.
      r1 =28° (Penalize □(1/2)mk for unit not given i.e degrees in all angles) (1mk)
   2. Produce P4P3 to meet RM produced. Measure angle d.
      d =37° (1mk)
   3. Draw the normal at D and measure the angle r2.
      r2 =30° (1mk)
3. Given that R= r1+ r2. Calculate R.
   R=28°+ 30° (Correct substitution = 1/2mk)
   =58° (Correct evaluation = 1/2mk)
4. Given that n=sin⁡((R+d)/2)/sin⁡(R/2) , find the value of n.
   n=sin⁡((58+37)/2)/sin⁡(58/2) (Correct substitution = 1mk)
   =sin⁡ 47.5/sin⁡29 (Correct evaluation = 1mk)
   n=1.521 (unitless 4sf=1mk)
5. Given that n sin⁡ k=1, find the value of k.
   nsin⁡k=1
   1.521sin⁡k=1 (Correct substitution = 1mk)
   sin⁡ k=1/(1.521)
   k⁡= sin^-1⁡ 1/(1.521)
   =41.11° (Correct evaluation = 1mk)
   1. What Physical property does n represent?
   2. Refractive index of glass (1mk)

PART B

6. Measure 100 ml of water and pour it into the beaker. Place the beaker on the bench. Clamp the thermometer vertically and insert it into the beaker with hot water.
   
   
7. Start the stop-watch when the temperature is 800 C. Record the temperature, θ and temperature, T (θ converted to Kelvin) after 4 minutes.
   1. θ = ……68. 0 ± 2.0……….°C. (1dp a must) (1mk)
   2. T =273 + 68
      = 341………..K. (1mk)
8. Find the mass, m (in kg) of water in the beaker given that the density of water is 1000kg/m³. (2mks)
   m=ρv
   = 1000 x 0.0001
   = 0.1 kg
9. Given that: γ=(mc(353-T))/240 where; m is the mass of the water used and the specific heat capacity of water, c = 4200J/kg/K, determine the value of γ. (3mks)
   γ=(0.1x4200(353-341))
                  240
   =5040/240
   =21 Js^(-1)
10. State the significance of γ. (1mk)
    Rate of energy loss by water / power loss by water