Physics Paper 3 Questions and Answers with Confidentials - Form 4 End Term 1 Exams 2022

Questions

1. You are provided with the following apparatus
   • A metre rule
   • Two stands
   • A pendulum bob
   • Some plasticine
   • Stop watch
   • Two pieces of strings (long and short one)
     
     Proceed as follows:
     1. Attach one end of the length of string to the metre rule at 10cm mark. Mark by use of a sliding loop of string round the meter rule.
     2. Fix the string at this point with the small bob of plasticine.
     3. Tie the string in a second loop at 90cm mark so that the string is stretched tight between the two marks.
     4. Fix this loop with a small plasticine. Attach the pendulum bob to the centre of the string so that the centre of gravity is 15cm below the point of suspension.
     5. If the attachments of the pendulum bob to the pieces does not produce a V-shape. Squeeze the string at the knot between the thumb and the fore finger.
        
        
        1. Measure the angle 2θ (1mk)
        2. Pull the pendulum bob towards you through a small distance, release it; measure the time (t) of the motion by timing 10 oscillations.
        3. Remove the plasticine at B and slide the loop towards A by 4cm and repeat (ii) above for other distances AB as shown in the table below.
           Table (a)
           

           Length from A and B(cm)	80	76	72	68	64	60
           Time for 10 oscillations(s)
           Period time T(s)
           T2(s2)
           2θ
           θ
           Cos θ

     6. Plot a graph of T2 against Cosθ (5 marks)
     7. Find the slope “s” of the graph. (3 marks)
     8. Given that k=^1.6²/_s find k. (2 marks)
2.                
   1.  
      1. You are provided with the following apparatus:
         • Resistance wire fitted on a scale labelled MN
         • Switch
         • Voltmeter
         • Ammeter
         • Two dry cells
         • Six connecting wires
           1. Set up the apparatus as shown in the figure below;
              
           2. Remove the crocodile clip to the resistance wire such that MN and close the switch. Record the voltmeter reading.
              Y=………………………………………..V (1mk)
           3. Attach the crocodile clip to the resistance wire such that L=10cm
           4. Record the voltmeter and ammeter readings in the table below
           5. Repeat the procedure in (iii) and (iv) for L=20cm, 30cm, 50cm, and 80cm
           6. Complete the table below; (5 marks)
              

              Length L=cm	10	20	30	50	80
              Curent 1(A)
              p.d V (v)
              Y-V
              v         y-v
              R= V/I

      2. Plot a graph of R (vertical axis) against ^v/_y-v (5 marks)
      3. Determine the slope m of the graph (2marks)
      4. The graph is given by the equation R=^5m/_vy-v+d determine the value of m and d (2 marks)
         
         
   2. You are provided with the following set of apparatus
      • A metre rule
      • A white screen
      • A candle
      • Lens and lens holder
        
        Procedure
        1. Set up the apparatus as shown
           
        2. Starting with L₁=30cm, adjust the position of the candle in order to obtain a sharp image on the screen. Record the value of L₂………………………………………. (1mk)
        3. Repeat the procedure for L₁=60cm
        4. Fill and complete for values of L₁/L₂ below. (3 marks)
           

           L1cm	L2cm	L1/L2
           30
           60

        5. Given the equation
           F1 =     L ₁
                    m+1
           When m=magnification determine the value of focal length f, (2 marks) 

Marking Scheme

1.     
   1.   
   2.  
   3.     
   4.      
   5.       
      1.    
         

         Length from A and B(cm)	80	76	72	68	64	60
         Time for 10 oscillations(s)	10	11	12	13	14	15
         Period time T(s)	1.0	1.1	1.2	1.3	1.4	1.5
         T2(s2)	1.00	1.21	1.44	1.69	1.96	2.25
         2θ	150°	138°	130°	108°	104°	96°
         θ	75n	69n	65n	54n	520	48n
         Cos θ	0.2588	0.3883	0.4226	0.5878	0.6157	0.6691

   6.  
      
2.                 
   1.      
      1.          
      2. V=2.7 volts   
      3.        
      4.      
      5.        
      6.  
         

         Length L=cm	10	20	30	50	80
         Curent 1(A)	0.86	0.48	0.43	0.255	0.205
         p.d V (v)	2.1	2.3	2.4	2.5	2.6
         Y-V	0.6	0.4	0.3	0.2	0.1
         v         y-v	3.5	5.75	8.0	12.5	26
         R= V/I	2.442	4.792	5.581	9.804	12.683

      7.      
         
   2.           
   3. d= 2.6Ω intercept omn R axis
      Part B
      

      L1cm	L2
      30	50.0 ± 2	0.60
      60	27.5 ± 2	2.18