Physics Paper 2 Questions and Answers - Maranda High Pre Mock Exams 2023

 Instructions to candidates  

• This paper consist of TWO sections; A and B. Answer ALL the questions in section A and B in the spaces provided.
• ALL working MUST be clearly shown. Mathematical tables, electronic calculators and slide rules may be used.
  Take: density of water = 1gcm⁻³ , g = 10N/kg

SECTION A (25 MARKS)

Attempt ALL questions in this section in the spaces provided

1. State two factors which determine the velocity of sound in air. (2 marks)
2.  Explain why electric power is not transmitted at low voltage (1 mark)
3.  
   1. State one similarity between X-rays and gamma rays (1 mark)
   2. State one difference between X-rays and gamma rays (1 mark)
   3. Describe one safety measure to be taken when handling these radiations. (1 mark)
4.  Figure 1 shows a wave moving through a convex section of a medium. 
   
   
   1. Complete the diagram to show the path of the rays (1 mark)
   2. State the property of waves illustrated above (1 mark)
5. When an object is placed 12 cm from a concave mirror, an image of height 4 cm is formed 24 cm from the mirror. Find the height of the object (2 marks)
6. Figure 2 shows two plane mirrors M1 and M2 are inclined to each other at an angle of 70°.
   
                      Figure 2
   If ray D is reflected ray from mirror M2, complete the path of the rays and hence determine the angle of incidence of on M1 (3 marks)
7. The p.d across a resistance wire is 12V. Find the quantity of electric charge flowing through the wire to generate 1.68 kJ of heat energy in one second. (3 marks)
8.  
   1. What is a hard magnetic material? (1 mark)
   2. Figure 3 shows a soft iron bar and a steel bar are suspended inside a coil above a container of iron filling.
      
                                         Figure 3
      Explain what is observed when switch K is closed (2 marks)
9. Figure 4 shows a sound wave produced from a tuning fork vibrating at 800 Hz
   
                                              Figure 4
   Calculate the velocity of the wave in the medium.     (3 marks)
10.  
    1. When a charged glass rod is brought near a gold leaf electroscope, the leaf diverges but fall again when the rod is removed. Explain the observations (2 marks)
    2. State any one precaution that should be observed when working with an electrostatic device. (1 mark)

SECTION B: (55 MARKS)

Attempt ALL questions in the spaces provided

11. Figure 5 shows an object O placed in front of a pinhole camera. Use it to answer the questions that follow;
    
    
    1. Use ray diagrams to locate the position of image (2 marks)
    2. State the characteristics of the image formed (3 marks)
    3. Increasing the size of the pinhole makes the image to be brighter but blurred. Explain why the image is;
       
       1. Brighter (1 mark)
       2. Blurred (1 mark)
    4. An object 1.6 m long is placed 8m from a pinhole camera which is 20 cm long.
       1. Calculate the height of the image (2 marks)
       2. What will be the height of the image formed if the camera is 10 cm long (2 marks)
12.  
    1. Define the term principal focus of diverging mirror (1 mark)
    2. With an aid of a well labeled diagram, describe an experiment to determine the focal length of a convex lens using an illuminated object and plane mirror. (5 marks)
    3. State two differences between the operation of a lens camera and the eyes (2 marks)
    4.  
       1. By completing the diagram in figure 6(a) explain shortsightedness of the eye (3 marks)
          
       2. Complete the Figure 6(b) to illustrate how the above defect is corrected (2 marks)
13. Figure 7 shows a ray of white light incident on a glass prism.
    
    
    1. Complete the diagram to show effect of the glass prism on the ray. (2 marks)
    2. State two effects caused by the glass prism on the white light (2 marks)
    3. Find the critical angle for glass in air if the refractive index of the glass is 1.5. (3 marks)
    4. State what happens when the above critical angle is exceeded (1 mark)
    5. Figure 8 shows how a mirage is formed. Complete the diagram to show how the mirage is formed and seen by the eye (2 marks)
       
                                              Figure 8
14.  
    1. State the reason why soft iron is laminated (1 mark)
    2. State one property of soft iron that makes it suitable for use as a transformer core (1 mark)
    3. Figure 9 shows a step-down transformer..
       
       
       1. Name the coils marked A and B (2 marks) ……………………………………………………………………………………………
       2.  If the transformer is used to step down mains supply from 480 V to 24V and coil A has 800 turns, determine the number of turns in coil B. (3 marks)
    4. Figure 10 shows pendulum A and pendulum B freely suspended between the poles of identical magnets. Pendulum A is made of thick copper plate while B is made of copper plate with slots
       
       
       1. When the two are set to swing, it is observed that A slows down faster than B Explain this observation. (2 marks)
       2. State one application of the concept illustrated in pendulum A (1 mark)
15.  
    1. Figure 11 shows three capacitors of capacitance 3μF, 2μF, 6μF and 12V supply connected in. a circuit.
       
       Calculate:
       
       1. The total capacitance of the circuit. (2 marks)
       2. The charge stored in the circuit. (2 marks)
       3. The potential difference across the 6μF capacitor. (2 marks)
    2. Figure 12 shows an arrangement of resistors. Use it to answer questions that follow. 
       
       1. Calculate the total resistance in the circuit. (3 marks)
       2. Calculate effective current in the circuit. (2 marks) 

MARKING SCHEME

1.  
   • Density of air
   • Humidity of air
   • Temperature of air
2. At low volytrage, current is high hence higher power loss dur to I²R ✓1
3.  
   1. Both travel at a speed of 3.0 × 10²m/s electromagnetic in nature. ✓1
   2. X-rays originate in the electron fields surrounding the nuclues , while gamma rayus moriginate form the nuclues ✓1
   3.  
      • Always wear gloves when handling them ✓1
      • Avoid direct exposure to the radiations.
4.  
   1.  
      
   2. Refraction ✓1
5. v = h_i
   u    h_o 
   24cm = 4cm  ✓1
   12cm      h_o  
   h_o = 2cm ✓1
6.  
   
   Angle of incidence on M₁ = 40° ✓1
7. H = Vlt ✓1
   1680 = 12 × 1 ×1
   l = 140A ✓1
   Q = lt 
       = 140 × 1
      = 140c ✓1
8.  
   1. It is a magnetic material that is hard to magnetize but which when magnetize, retains its magnetism for long. ✓1
   2.  
      • Soft iron bar attracts iron fillings first, and more than the steel bar. ✓1
      • Soft iron bar is easily magnetized. while steel bar is difficult. ✓1
9.  ½λ = 20cm
       λ = 40cm
   V = fλ
      = 800 × ⁴⁰/₁₀₀
      = 320m/s
10.  
    1.  
       • Leaf diverges because the glads rod repels like charges, and attracts unlike charges✓1. It falls again when the rod is removed, since the electroscope acquires a temporary charge. ✓1
       • Avoid direct hand/ body contact instead, wear gloves and proper clothing.✓1
11.  
    1.  
       
    2.  
       
       • Magnified  ✓1
       • Inverted/Upside down ✓1
       • Focused on screen /real  ✓1
    3.  
       1. Larger hole allows more light into the pinhole ✓1
       2. Larger hole causes more images which overlap. hence blurred ✓1
    4.   
       1. h_i  = v
          h_o = u
             h_i   = 0.20m  ✓1
          1.6m       8m
           h_i = 0.04m/4cm ✓1
       2. h_i  = v
          h_o = u
             h_i   = 0.20m  ✓1
          1.6m       8m
          hi = 1.6m × 0.01m
                          8
             = 0.02m/2cm ✓1
12.  
    1. A point from which all rays close to and parallel to the principal axis appear to diverge from after reflection by the mirror. ✓1
    2.  
       1. Apparatus: Matre rule, lenw-holder, candle, screen cross wires ✓1
       2. Procedure 
          • Set the lens in its holder with a plane mirror behind it so that light passing through it can be reflectes back as shown below.
            
          • Adjust the po;sition of the lens until a sharp image of the cross- wire is formed alongside (close to ) the cross- wire ✓1
       3. Conclusion: The distance between the object and the centre of the lens, gives the focal length of the lens. ✓1
    3.   
       • Focal length of the eye lens changes while that of the lens camera is constant ✓1
       • The distance between the lens and film in a lens camera can be varied by zooming, while the distnace between the eye lens and the retina is constant. ✓1
       • A camera can take only one photo at a time when the shutter is open, while the eye forms constantly changing pictures. ✓1
    4.  
       1.   
          
                           Figure 6(a)
          Rays for distant objects are focused in front of the retina due to short focal length of the eye and long eye ball. ✓1
       2.  
          
                                     Figure 6(b)
13.   
    1. 
       
    2.  
       • Dispersion - Separation of white light into its component colours.  ✓1
       • Refraction - change in speed of light .  ✓1
    3. Sin C = ¹/_n  ✓1
       Sin C = ¹/_1.5  ✓1
       Sin C = 0.6667
       C = Sin⁻¹ 0.6667
        = 41.81°  ✓1
    4. Total internal reflection occurs.  ✓1
    5.  
       
14.  
    1. To reduce eddy currents (small currents that result from the changing magnetic field created by the alternating current in the primary coil) ✓1
    2. Easily magnetized and demagnetized  ✓1
    3.  
       1.  
          • A - primary coil ✓1
          • B - Secondary coil ✓1
       2. N_s = V_s ✓1
          N_p    V_p
          N_s   =   24   ✓1
          200      480
          N_s = 800 × 24
                       480
          N_s = 40turns  ✓1
    4.  
       1. Copper plate with slots experiences slower motion hence lower damping  ✓1 which will result in a smooth stopping compared to the thick copper plate with higher motion. ✓1
       2.  Hot wire moving coil and induction type instruments (eddy current damping) ✓1
15.  
    1.  
       1. CT = 3 × 8 ✓1
                   3 + 8
                = 2²/₁₁μF / 2.1818μF ✓1
       2. Q = CV ✓1
              = 2.1818 × 12
              = 26.1816 μC ✓1
    2.  
       1. Rp1 = (¹/₆ + ¹/₂ + ¹/₃)⁻¹ = 1Ω  ✓1
          Rp2 = 6 × 3 = 2Ω  ✓1
                     6 + 3
          RT = 1Ω + 3Ω + 2Ω
               = 6Ω ✓1
       2. l = ^V/_R
            = ¹²/₆ ✓1
            = 2A ✓1