Physics Questions and Answers - Form 2 Term 2 Opener Exams 2022

QUESTIONS

1. A spherical ball bearing of mass 0.0024 kg is held between the anvil and spindle of a micrometer screw gauge. Use this information and the position of the scale in the figure below to answer the questions (a) and (b) below:
   
   
   1. What is the diameter of the ball bearing? (1 mk)
   2. Find the density of the ball bearing  correct to 3 significant figures (3 mks)
2. Explain why it is dangerous for a bus to carry standing passengers. ( 2 mks)
3. Differentiate between cohesive and adhesive forces.  (2mks)
4. Explain the cause of random motion of smoke particles as observed in Brownian motion experiment using a smoke cell. (2mks)
5. The Figure 2 shows two identical thermometers. Thermometer A has a blackened bulb while thermometer B has a silvery bulb. A candle is placed equidistant between the two thermometers
   
   State with a reason the observations made after sometime (2 mks)
6. Give a reason why water is not suitable as a barometric liquid. (1 mk)
7. A uniform metre rule is balanced as shown below.
   
   Find the weight of the metre rule (3mrks)
8. State the difference between a soft magnetic material and a hard magnetic material.(1 mk)
9. The Figure  shows a scale of part of a vernier calliper.
   
   What is the actual reading indicated by the scale if the vernier caliper has a zero of +0.02cm. (2mks)
10. A uniform plank of wood is pivoted at its centre. A block of wood of mass 2 kg is balanced by a mass of 1.5 kg placed 30 cm from the pivot as shown in the diagram below.
    
    Calculate the distance X. (3mks)
11. A highly negative charged rod is gradually brought close to the cap of a positively charged electroscope. It is observed that the leaf collapses initially and the leaf diverges. Explain this observation (2mks)
12. State the right hand grip rule.(2maks)
13. The figure below shows an object O and its image I formed by a concave mirror.
    
    Using suitable rays, to locate the focal length of the mirror. (3mks)
14. The figure below shows a uniform rectangular lamina.
    
    Locate and indicate the centre of gravity of lamina. (3mks)
15. Use the information below to answer questions below
    In an experiment to determine the density of a liquid, the following readings were made.M
    ass of empty density bottle = 20g
    Mass of bottle filled with water = 70g
    Mass of bottle filled with a liquid = 695g
    1. Find the density of the liquid, given that density of water is 1000kgmˉ³. (4mks)
    2. Find the mass of the liquid. (2mks)
16. In an attempt to make a magnet, a student used the double stroke method as shown below. 
    
    State the polarities at the ends A and B (2mks)
    A………………………………………B……………………………………
17. An object  is placed 30cm in front of a concave mirror of focal length 20cm. Determine
    1. Size of the image. (3mks)
    2. Magnification (2mks)
    3. Name two applications of concave mirrors (2mks) 
18. A metre rule is balanced by masses 18g and 12g suspended from its ends. Find the position of its pivot. (3mks)
19. Explain the function of constriction present in a clinical thermometer. (1mrk)
20. Define the term moment of force. (2mrks)
21. State the two laws of reflection (4mks)
22. Give that the diameter of an oil drop is 0.15cm and the diameter of a circular patch formed by the same drop on water is 35.35cm.Calculate the thickness of the oil molecule. (4mks)
23. State two differences between mass and weight.(2mks)
24. Name two factors that affect stability of a body(2mrks)
25. The figure 2, below, U-tube contains two immiscible liquids P and Q. If the density of Q is 900kg/m³ and that of P is 1200kg / m³, Calculate the height of liquid Q. (3 marks)
    
26. State two defects of a simple cell (2mks)

MARKING SCHEME

1.        
   1. 4.71mm
   2.       
2. The position of CoG will be raised making the bus unstable
3.                
   1. Cohesive force is the force of attraction between molecules of the same kind
      Adhesive force is the force of attraction between molecules of the differnt kind
   2. Air molecules are in constant random motion they bombard the smoke particles randomly
4. Thermometer a will record a high value. Dull surfaces are good absorbers of heat energy
5. It gives a long measurable column of about 10m
6. W= 3.333N
7. Soft magnetic materials are materials which are easily magnetized and they don’t retain they magnetism for so long.
   Hard magnetic materials are materials which are not easily magnetized and they  retain they magnetism for so long.
8. 10.44 – 0.02 = 10.42cm
9. X = 22.5g
10.            
11. The right hand grip rule states that if a coil carrying a current is grasped in the right hand such that the fingers point in the direction of current in the coil, then the thumb points in the direction of North Pole.
12.        
13.        
    
14.      
    1. 13.5g/cm³
    2. 675g
15. A South pole B North pole
16.          
    1. 60cm
    2. 2
    3. Shaving mirrors
       By dentist in examining teeth
       In telescopes for astronomical observations
       Solar concentrators
17. 18 * x = 12(100-x)
    X =40cm mark
18. Prevent backflow of mercury before the nurse record the temperature 
19. Moment of a force is the product of the force (F) and the perpendicular distance from the line of  of the force and the point of support
20. The incident ray, the reflected ray and the normal at the point of incidence all lie on the same plane.
    The angle of incidence, i, equals the angle of reflection, r.
21.          
22. Differences between mass and weight 
    

    Mass	Weight
    1. Its a quantity of matter on a body 2. It’s measured in kg. 3.Same  everywhere . 4. Measured using a beam balance. 5.Has magnitude only (scalar quantity)	1.It is a pull of gravity on a body .  2. It is measured in (N) 3. Varies from one place to another. 4.Measured using a spring balance 5.Has both magnitude and direction.(vector quantity)

23. The area of the base
    The position of the centre of gravity
24.            
25. Polarisation 
    Local action