Physics Paper 3 Questions and Answers with Confidential - Mangu High School Mock Exams 2023

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INSTRUCTIONS TO CANDIDATES
  • Answer all questions in the spaces provided.
  • You are supposed to spend the first 15 minutes of the 2½ hours allowed for this paper reading the whole paper carefully before commencing your work.
  • Marks will be given for clear records of observations actually made, their suitability, accuracy and the use made of them.
  • Candidates are advised to record their observations as soon as they are made.
  • All working must be clearly shown where necessary.
  • Mathematical tables and silent electronic calculators may be used.

Question one

This question has two parts A and B.  Answer both parts.

PART A

You are provided with the following:-
  • A retort stand, clamp and boss.
  • A spiral spring.
  • A stop watch.
  • Three 100g masses.

Proceed as follows:

  1. Suspend a 100g mass at the end of the spring as shown in figure 1.
    F4PhysManguMP32023Q1
                           Fig. 1
    Now give the mass a small vertical displacement and release so that it performs vertical oscillations.  Time ten oscillations and determine the period T. Enter your results in table 1.
  2. Repeat the experiment for the other values of mass and complete the table.
    Table 1
     Mass m (g)  100  200  300
     Time for 10 oscillations (s)      
     Periodic time T(s)      
    (3mks)
  3. Given t)hat T = π√(m/K), where k is the spring constant, find the average value k for the spring.            K (2mks)

    PART B
    You are provided with the following:-
    • A 250ml glass beaker
    • A Bunsen burner
    • A Thermometer
    • A Stop watch
    • A Tripod stand and a Wire gauze
    • A measuring cylinder 100ml
    •  Water
      Set the apparatus as shown in figure 2 below.
      F4PhysManguMP32023Q1b
                                             Fig. 2
  4. Measure 100cm3 of water and pour it into the beaker.  Take the initial temperature of the water.
    T0 = …………………………………………….°C (1mk)
    Now heat the water to a temperature of 800C.  switch off the gas tap and place a thermometer into the beaker and start the stop watch when the temperature is 65°C.  Take the temperature T°C of water ever two minutes.  Record your results in the table 2 below.

    Table 2
     Time, t(min)  2  4  6  8  10  12  14
     Time, t(min)              
     (T - T0)              
     Log (T - T0)              
    (5mks)
  5. Plot a graph of Log (T - T0) against Time (t). (5mks)
  6. Find the value of P of log (T - T0) when t = 0. (1mk)
  7. Determine N, where N is the antilog of P. (1mk)
  8. Calculate the temperature of the surrounding TR using the expression N = 65 – T              (2mks)

Question 2 

Part A

You are provided with the following:-

  • A lens and a lens holder.
  • A candle.
  • A white screen.

Proceed as follows:

  1. Set the apparatus as shown below.
    F4PhysManguMP32023Q2
  2. Place the white screen at a distance X = 100cm from the candle.  Let the lens be at position P, adjacent to the lit candle.
  3. Move the lens towards the screen until an enlarged image of the candle is formed on the screen.  Measure and record the distance u1.
  4. Move the lens to a second position Q where the image of the candle is sharp but diminished on the screen.
    Measure and record the distance u2.
    Hence determine the value of d = u2 - u1.
  5. Repeat the procedure in (c) and (d) for either values of x = 95, 90, 85, 80cm.  Complete table 2 shown below.

    Table 2
     x(cm)  100  95  90  85  80
     u1(cm)          
     u2(cm)          
     d = u2 − u1(cm)          
     y = d2(cm) (2 d.p)
            x
             
    (8mks)
  6. On the grid provided, plot a graph of y against x. (5mks)
  7. Determine the value of x = x0, when y = 0. (1mk)
    x0 = …………………………………………… cm
  8. Given that k = xo, determine the value of k. (1mk)

    PART B
    You are provided with the following:-
    • A voltmeter
    • A resistance wire labelled R mounted on a metre rule.
    • A metre rule.
    • A resistance wire labelled T mounted on a small piece of carton.
    • Two dry cells and a cell holder.
    • Six connecting wires, each with a crocodile clip at one end.
    • A switch.

      Proceed as follows;
  9. Measure and record the e.m.f. E0 of the cells connected in series, E0 = ____ v.   (1mk)
  10. Connect the circuit as shown below.  Point O on resistance wire P is at 50cm mark of the metre rule.  A and B are points on resistance wire P such that AO = OB = X = 30cm.
    F4PhysManguMP32023Q2b
  11. Close the switch.  Read and record the potential difference V across AO
    V = …………………………………………. Volts. (1mk)
  12. The relationship between V and x is given by:
    I/V = 35/x + 1/y
    Determine the value of y. (2mks)
  13. Use the e.m.f. E0 to determine the constant k, given that:
    k     =     8      (1mk)
               35E0 

CONFIDENTIAL

QUESTION 1

Each candidate should have:-

  • A retort stand, clamp and boss
  • A spiral spring
  • A stop watch
  • Three 100g masses
  • A 250ml glass beaker
  • A Bunsen burner
  • A thermometer (-10 to 110°C)
  • A tripod stand and wire gauze
  • A measuring cylinder 100mll
  • A source of heat
  • Some water in a container about 500ml

QUESTION 2  

Each candidate is required to have the following apparatus:

  • A voltmeter (0 – 5V)
  • A candle
  • A white screen
  • Two new dry cells
  • Six connecting wires, each with a crocodile clip at one end.
  • A switch.
  • A lens and a lens holder. NB: Focal length = 20cm.
  • A metre rule.
  • A resistance wire labelled R mounted on a metre rule.
    The physics teacher is required to mount a nichrome wire SWG 28 on a metre rule and label the wire R. The diameter of the wire is 0.36mm.
  • A resistance wire labelled T.
    The Physics teacher is required to mount a nichrome wire SWG 28 on a small piece of carbon box and label it T.
    The diameter of the wire is 0.36mm and its length is 60cm.

F4PhysManguMP32023Conf

MARKING SCHEME

Question one

(a)  Table 1

 Mass m (g)  100  200  300
 Time for 10 oscillations, (s)  4.75  6.74  8.02
 Periodic time T (s)  0.475  0.674  0.0802
 
 Award 2 mks 3 correct values for 10 oscillations to 2 d.p
1 mk for two correct values
Award 1mk for correct evaluation of T
(c) T = π√(m/k)    (2 marks)
{ K1 = 4.375, K2 = 4.346, K3 = 4.605} award 1mk
K = 4.442 kg/m or 44.42 N/m   award 1mk
(d) T0 = 23.0 °C
 
Table 2
 Time, t(min)  2  4  6  8  10  12  14
 Temperature (T) °C  61.0   57.0   53.0   51.0   49.0   47.0   45.0 
 (T - T0)  38.0  34.0  30.0  28.0  26.0  24.0  22.0
 Log (T - T0)  1.580   1.531   1.477   1.447   1.415   1.380   1.342
 
Award ½ mark for @ correct value of T up to a max of six points
Award 1 mark for correct evaluation of (T - T0)
Award 1 mark for correct evaluation of log (T - T0)   
(e) On the grid paper.
  • Plotting P = 2 marks
  • Scale S = 1mk
  • Labelling axes A = 1mk
  • Line L = 1 mark with −ve gradient

F4PhysManguMP32023Ans1e

(f) P = y-intercept
     − 1.61   1 mk
    Evidence form the graph

(g) N = the antilog of P
     = antilog of 1.61
     = 40.74°C 1mk

(h) N = 65 − TR
     40.74 = 65 − TR    1 mark
     TR = 24.26°C

Question two

(e)  Table 2
 x(cm)  100  95  90  85  80
 u1(cm)  25.0  27.0  29.0  30.0  32.0  ±1.0cm
 u2(cm)  71.0  64.0  61.0  52.0  48.0  ±1.0cm 
 d = u2 − u1(cm)  46.0  37.0  32.0  22.0  16.0
 y = d2(cm) (2 d.p)
        x
 21.16  14.41  11.38  5.69  3.20
(8mks)
u1 and u2 values each ½ mk
d value a maximum of 1 mark 4 – 5 = 1mk
                                            3 values = ½ mark
y value a maximum of 2 marks correct to 2d.p
4 – 5 = 2 marks
     3   = 1 mark
(f)  Axes with units = 1 mark (each axis = ½ mark)
Simple and uniform scale = 1 mark (vertical axis only)
Plotting within 1 small square = 2 marks (4 – 5 = 2 marks)
                                                                   (3 = 1 mark)
Straight line drawn with a ruler = 1mark
(Line should have positive gradient and passes at least 3 plotted points)
 A GRAPH OF y(cm) AGAINST x(cm)
F4PhysManguMP32023Ans2m
(g)  Xo = 80cm ± 1cm
(h) k = Xo = 80 = 20cm ± 0.5cm
             4      4
(i) Bo = 3.0v ± 0.1v
(k) v = 0.40 volts ± 0.05v
(l) = 35 +
     v      x     y
         =  1    = 35 +
            0.40    30    y
      y = 0.75v
(m)  k =   8       8    = 0.07619 or 0.0762 v-1
            35Eo    35x3
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