Physics Questions and Answers - Form 1 End Term 2 Exams 2022

Questions

INSTRUCTIONS TO CANDIDATES:

• The paper consist of two Sections A and B. Answer all the questions in the spaces provided.
• Mathematical tables may be used.

SECTION A - (40 MARKS)

1. Define the term physics. (1 mark)
2. State three career opportunities related to physics. (3 marks)
3. The table below shows some basic quantities and their SI units. Complete the table to show the missing entries. (2 marks)
   

   	Quantity	S.I Unit	Symbols
   1		Candela
   2	Amount of substances

4. A stone of mass, 40g was completely immersed in a liquid. The levels of the liquids are shown in the figure.
   
   Determine the density of the stone in SI unit. (2 marks)
5.      
   1. One of the factors that affect surface tension is temperature of the liquid. State one other factor. (1 mark)
   2. Use surface molecules A, B, C and inner molecule D shown below, to explain why surface of a liquid is under tension. (2 marks)
      
6. Name two forces that determine the shape of a liquid drop on a solid surface. (2 marks)
7. 1800cm³ of fresh water of density 1000kg/m3 is mixed with 2200cm3 of sea water of density 1025kg/m3. Calculate the density of the mixture (4mks)
8. State the reason why it may not be possible to suck a liquid in to your mouth using a drinking straw in the surface of the moon. (1 mark)
9. In building construction, beans made of concrete are reinforced with steel. Explain. (2 marks)
10. When a liquid is heated in a glass flask, its level first falls and then rises. Explain this observation. (2 marks)
11. Name the thermometric liquid that is most suitable to use in very cold places. (1 mark)
12.      
    1. State one factor which makes gases compressible. (1 mark)
    2. The figure below shows a set up used to demonstrate Brownian motion in gases.
       
       State the role of the; (3 marks)
       1. Convex lens.
       2. Microscope.
       3. Beam of light.
    3. Define the term diffusion. (1 mark)
13. Highlight two factors which shows that heat from the sun does reach the earth surface by convection. (2 marks)
    1. The figure below shows some wax at the end of a copper rod.
       
       State three factors that affect the rate at which the wax melts. (3 marks)
14.  
    1. Define force and give its S.I units (2mks)
    2. State three effects of force on an object (3mks)
    3. Name and show forces acting on a box placed on a table. (2mks)
       

SECTION B - (30 MARKS)

16. A ream of foolscaps containing 500 papers has a thickness of 50mm and a mass of 2kg. if it has a width of 200mm and a length of 300mm, find;
    1. The thickness of one sheet of paper (2 marks)
    2. The mass of one sheet of paper (2 marks)
    3. The volume of one sheet of paper (3 marks)
    4. The density of the paper. (3 marks)
17.  
    1. Two identical aluminium rods shown in the figure below are heated by the same Bunsen burner. One rests on a metal block and the other on a wooden block.
       
       State with a reason which wax is likely to melt. (2 marks)
    2. Two identical cans A and B were each filled with hot water at the same temperature and covered with an air tight lid as shown below.
       
       Given that the outer surface of can A is dull while that of B is shiny, state with a reason which thermometer would show lower temperature after ten minutes. (2 marks)
    3. State the purpose of the following features of a thermometer. (3 marks)
       1. Narrow capillary bore.
       2. Thin bulb.
       3. Thick glass stem.
    4. State three properties of mercury that makes it a good thermometric liquid. (3 marks)
18. States the reason why it is not correct to quote the weight of solid objects in kilograms. (1 mk)
19. Wasike found that the width of his desk was approximately 10 palm-lengths. If his palm was 15.0cm long, what was the width of his desk in metres? (3 mks)
20. Describe how to estimate the height of a tree using a rod of about 2m long and a tape measure.(3 mks)
21. The mass of an empty density bottle is 20g its mass when filled with water is 40.0g and 50.0 when filled with liquid x. Calculate the density of liquid X if the density of water is 1000kgm-3. (3 mks)

Marking Scheme

SECTION A - 40 MKS

1. The study of matter in relation to energy. 1 mk
2. Career opportunities.
   • Engineering (mechanical, electrical, civil, electronics etc)
   • Physics teacher
   • Pilot.
   • Computer scientist.
   • Surveyor. (any other relevant) (any three) (1 x 3)
3.        
   

   Quantity	S.I unit	Symbols
   Luminous intensity	Candela	Cd
   Amount of substances	Mole	Mol

   Both correct - one mark.
   only one correct – zero
4. m = 40 g or                       m = 40 g
   = 0.04 kg                         r = (50 - 40)
   v = 50 - 40                            = 10 ml
   = 10 ml                                = 10 cm³
   = 0.0000 1 m³
   ζ =      0.04                          ζ =    40   = 4 gcm ^-3
           0.00001                               10
   = 4000 kg /m³                      =  4,000 kgm^-3
5.      
   1. Presence of impurities.
   2. Molecule D experiences equal forces in all directions hence zero resultant force. The surface molecules A, B and D are only pulled inwards and no outward force for balancing hence under tension.
6.  
   • Adhesive force.
   • Cohesive force.
7. Density of mixture = mass of mixture
   Volume of mixture
   Mass of fresh water = 1800 x 1 =1800g
   Mass of sea water = 2200 x 1.025 = 2255g
   Density of mixture =       2255 + 1800        
                                        1800 + 2200
   = 1.01375g/cm3
8. Absence of atmospheric pressure.
9. Concrete and steel have the same linear expansivity. They expand and contract at the same rate without breaking.
10. The flask receives the heat first and expands increasing its capacity later the heat reaches the liquid which expands at a faster rate than the glass.
11. Alcohol..
12.          
    1. Large intermolecular distances.
    2.          
       • To focus light into the smoke cell.
       • To magnify the smoke particles.
       • To illuminate the smoke particles to make them more visible.
    3. Movement of molecules from a region of high concentration to a region of low concentration.
13.       
    • Convection requires a medium but between the sun and the atmosphere there is a vacuum.
    • Hot particles move upwards from the source.
14.      
    • Length of the rod.
    • Thickness / cross-section area of the rod.
    • Temperature difference.
      (reject type of motorial & amount of heat produced by the heater)
15.    
    1. Force is defined as a pull or a push S.I units = Newton (N)
    2.  
       • can make objects change direction of motion
       • Can make a stationary object start moving or increase the sped of moving object/cause acceleration
       • Slows down or stop a moving object
       • Distort (change shape) of an object
16.             
    1. thickness = 50/100 
       0.1mm
    2. mass= 2000  = 4g
                   500
    3. Colume = 5 x 20 x30  = 6cm³
                             500
       
       
    4. density = ⁴/₆ = 0.67g/cm³
17.  
    1. Wax B - Wood is a poor conductor and all the heat absorbed by the rod is used for melting the wax but the metal block conducts all the heat away.
    2. Thermometer A
       Dull surfaces are better emitters of heat that shinny surfaces.
    3.      
       1. To make thermometer more accurate / sensitive.
       2. Quick acting /quick transmission of heat, to the mercury.
       3. To magnify the scale.
    4.     
       • Has uniform expansitity.
       • Has does not wet the surface.
       • It is visible/opaque.
       • Good conductor of heat.
       • Has wide range of temperature
       • Very sensitive to heat. (any three)
18. The S.I. unit of measuring weight is Newton and not Kilogram.
19.      
    • 1 palm – Length is 15cm long
      10 palm – lengths
      = (10 x 15)cm
      =    150   = 1.5m
           100
20.       
    • Hold the rod upright and measure its length using the tape measure.
    • Measure the length of its shadow
    • Measure the length of the shadow of a tree in the school compound
    • Then relate the height of the tree from:
      
         Height of tree   
         Height of rod
      
      =      Length of the shadow of the tree   
              Length of the shadow of the rod
21.             
    • Mass of H₂O - 40 – 20 = 20g = 0.02kg
      Density of H₂O – 1000kg
      Volume of H₂O =    0.02   
                                  1000
      = 0.00002m³
      Mass of liquid x 50g – 20g = 30g = 0.03kg
      Volume = -0002
      Density of liquid = 1500kg/m³