Physics Paper 3 Questions and Answers with Confidential - Pavement Mock Exams 2021/2022

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INSTRUCTIONS TO CANDIDATES:

  • You are supposed to spend the first 15 minutes of the 2 ½ hours allowed for this paper reading the whole paper carefully before commencing your work.
  • Marks are given for a clear record of the observation actually made, their suitability, accuracy and the use made of them.
  • Candidates are advised to record their observations as soon as they are made
  • Non-programmable silent electronic calculators may be used.

QUESTION 1

You are provided with the following apparatus

  • One stand with the clamp and the boss
  • One 100g mass
  • 100cm long thread
  • Two pieces of wood
  • Stop watch
  1. Set up the apparatus as shown below.
    Phys PVM Q1a 2122 PP3
  2. Adjust the length L of the thread so that L=70cm. Give the mass m a slight displacement and release so that it oscillates freely. Measure the time t for twenty oscillations and record in the table below.
  3. Repeat the procedure above for other values of L as shown and complete the table.
     Length L (cm)   70   60   50   40   30   20 
     Length L(m)            
     Time for 20 oscillation             
     Period T(s)            
     T2(s2)            
    (9 marks)
  4. On the grid provided plot a graph of T2(s2) (y-axis) against L(cm)   (5 marks)
    1. Determine the slope of the graph (3 marks)
    2. Given that T2 = 4π² l determine the value of the constant g (3 marks)
                                 g

QUESTION 2

You are provided with the following apparatus

  • A wire mounted on a mm scale
  • 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

Procedure.

  1. Using the micrometer screw gauge, determine the diameter d of the wire at three different points.
    d1=……………………………………mm, d2=……………………………….mm, d3……………………………… mm,
    Average d = ………………………………..m (2 marks)
  2. Calculate the cross- sectional area A of the wire in m2      (2 marks)
  3. Set up the circuit as shown below.
    Phys PVM Q2c 2122 PP3
  4. Vary the length by using the crocodile clip along the wire from (when L =0). Record the voltmeter and ammeter readings in the table below. (5 marks)
     Length L (cm)   80cm   60cm   40cm   20cm   0cm 
     Current I (A)          
     Voltage (V)          
  5. Plot the graph of voltage V against current I (A) (5 marks)
  6. Determine the slope of the graph. (2 marks)
  7. Given that V = −Ir +E,
    1. calculate the internal resistance of the cell. (2 marks)
    2. Determine the emf (E) of the battery. (2marks) 

CONFIDENTIAL

QUESTION 1

Provided the following apparatus

  • One stand with the clamp and the boss
  • One 100g mass
  • 100cm long thread
  • Two pieces of wood
  • Stop watch

QUESTION 2

Provided the following apparatus

  • A wire mounted on a mm scale
  • 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

QUESTION 1

You are provided with the following apparatus

  • One stand with the clamp and the boss
  • One 100g mass
  • 100cm long thread
  • Two pieces of wood
  • Stop watch
  1. Set up the apparatus as shown below.
    Phys PVM Q1a 2122 PP3
  2. Adjust the length L of the thread so that L=70cm. Give the mass m a slight displacement and release so that it oscillates freely. Measure the time t for twenty oscillations and record in the table below.
  3. Repeat the procedure above for other values of L as shown and complete the table.
     Length L (cm)   70   60   50   40   30   20 
     Length L(m)  0.70   0.60   0.50   0.40   0.30   0.20 
     Time for 20 oscillation
     Range (36-15) 
     34.07   31.57   29.16   26.25   22.78   18.61 
     Period T(s)
     4s.f (a must)
     1.704  1.579   1.458   1.313   1.139   0.9305 
     T2(s2)
     4s.f (a must)
     2.902  2.492   2.126   1.723  1.286   0.8658 
    (9 marks)
  4. On the grid provided plot a graph of T2(s2) (y-axis) against L(cm)   (5 marks)
    Phys PVM Ans 1d 2122 PP3
    1. Determine the slope of the graph (3 marks)
      Slope = ΔT²
                    ΔL
                = 2.5 − 1.25
                   0.6 − 0.3
                = 4.1667s2/m
    2. Given that T2 = 4π² l determine the value of the constant g (3 marks)
                                 g
      slope = 4π²
                    g
      g =   4π²   
            4.1667
        = 9.475 m/s2 

QUESTION 2

You are provided with the following apparatus

  • A wire mounted on a mm scale
  • 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

Procedure.

  1. Using the micrometer screw gauge, determine the diameter d of the wire at three different points.
    d1=………… 0.35…………………mm, d2=……………0.34………….mm, d3……………0.36………… mm,
    Average d = 0.35 + 0.34 + 0.36   m (2 marks)
                                     3
                    = 0.35mm    = 3.5 × 10−4
  2. Calculate the cross- sectional area A of the wire in m2      (2 marks)
    A = πr2  
       = 3.142 ×
    (3.5 × 10−4)2  
                              2
      = 9.625 × 10−8m
  3. Set up the circuit as shown below.
    Phys PVM Q2c 2122 PP3
  4. Vary the length by using the crocodile clip along the wire from (when L =0). Record the voltmeter and ammeter readings in the table below. (5 marks)
     Length L (cm)   80cm   60cm   40cm   20cm   0cm 
     Current I (A)  0.25  0.30   0.40   0.60   2.0 
     Voltage (V)    2.5    2.4     2.3   2.2  0.2
  5. Plot the graph of voltage V against current I (A) (5 marks)
    Phys PVM Ans2e 2122 PP3
  6. Determine the slope of the graph. (2 marks)
    Slope = ΔV
                  ΔI
              = 2.0 − 2.75
                 0.65 − 0.05
              =  − 0.75
                    0.6
              = − 1.25Ω
  7. Given that V = Ir +E,
    1. calculate the internal resistance of the cell. (2 marks)
      V =  −Ir + E 
      Gradient =  −r
      −r =  − 0.125
       r = 1.25Ω
    2. Determine the emf (E) of the battery. (2marks) 
      Emf E = V − intercept
                 = 2.8v

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