Physics Paper 2 Questions - Mumias West Pre Mock Exams 2023

INSTRUCTIONS TO CANDIDATES:

• This paper consists of two sections, A and B
• Answer all questions in section A and B
• All working must be clearly shown
• Scientific calculators and KNEC Mathematical tables may be used
• Take g = 10m/s²

For Examiners’ Use Only

QUESTIONS

SECTION A (25 MARKS)

1. The figure 1 below shows the image in front of a mirror M
   
   By ray diagram construction, locate the position of the object (2mks)
2. Figure 2 below shows a sharp pin fixed on a cap of leaf electroscope The electroscope is highly charged and then left for some time
   
   Explain why the leaf collapses (1mk)
3. Explain how polarization reduces current in a simple primary cell State how it can be reduced (2mks)
4. Fig 3 below shows a ray incident on a converging lens
   
   Fig 3
   Complete the ray diagram by showing the emergent ray (1mk)
5. The chart below shows an arrangement of different parts of the electromagnetic spectrum
   

   Radio

   A

   Infrared

   Visible

   B

   X-Rays

   Gamma Rays

   1. Name the radiation represented by B (1mk)
   2. Name a device that can be used to detect radiation A (1mk)
6. An object is placed in between two parallel mirrors How many images can a student see?  (2mks)
7. A car battery requires topping up with distilled water occasionally Explain why this is necessary and why distilled water is used (2mks)
8. What causes electrical resistance in conductors? (1mk)
9. In determining the depth of an ocean, an echo sounder producing ultrasonic sound is used
   Give one reason why this sound is preferred (1 mk)
10. State the conditions necessary for a wave incident on a slit to be diffracted (2mks)
11. Figure represents a long horizontal insulated wire XY connected in an electric circuit The circle represents where a plotting compass is placed on the wire
    
    
    1. In the circle put an arrow to show the direction the N pole of the compass will deflect when switch k is closed (1mk)
    2. Mention any two ways of reversing the direction captured in (i) above (2mk)
12. The diagram below shows a permanent magnet suspended by a spring State with a reason the behavior of the magnet when the switch is closed (2mks)
    
13.                      
    1. Define principal focus as used in curved surfaces (1mk)
    2. An object OB is placed in front of a convex mirror as shown below drawn to scale
       
       
       1. Draw a ray diagram to show the position of the image formed (3mks)

SECTION B (55 MARKS)

14.                    
    1. State the basic law of electrostatics (1mks)
    2. Figure 3 shows a pear shaped conductor with positive charged on its surface
       
       Fig 3
       A proof plane is used to touch side B of the conductor and then the cap of an uncharged electroscope This is then repeated with side A
       1. Give the observation made on the electroscope in each case (2mks)
       2. What conclusion is drawn from the observation in (i) above (1mk)
       3. Draw on the diagram above the illustration of your conclusion in (ii) above (1mk)
       4. Name one application of such a conductor (1mk)
    3. The figure below shows an arrangement which may be used to charge a capacitor of capacitance 5µ0F and then to connect it to a capacitor of capacitance 20µF
       
       
       1. The switch S is first placed at position A, so that the capacitor C is connected to the 12V dc supply Calculate the charge stored in the capacitor (3mks)
       2. The switch S is now changed to position B Calculate the final potential difference across the capacitors (3mks)
15.                        
    1. Distinguish between transverse and longitudinal wave (2mks)
    2. The diagram below shows a transverse wave traveling in different media
       
       
       1. Name any two changes that the waves undergo in moving from medium I to medium II (2mks)
       2. State with reason which of the two media is denser (2mks)
    3. The diagram below represents a microwave travelling in air through points A and B
       
       The distance between A and B is 40 cm Determine the wavelength of the microwave shown in the figure (1mk)
    4. Sketch on the same figure another wave with half amplitude and double frequency (1mk)
    5. A starting pistol is fired 640 m away from a spectator
       
       The spectator hears the sound of the starting pistol two seconds after seeing the flash from the gun What is the speed of sound in air? (2mks)
16. The graphs in the figure below show the relation between the current I and the potential difference V for a resistor and a lamp
    
    
    1.                    
       1. Describe how, if at all, the resistance varies as the current increases in (2mks)
          • The resistor,
          • The lamp 
       2. State the value of the potential difference when the resistor and the lamp have the same resistance (1mk)
    2. The two components are connected in parallel to a supply of emf 40 V Calculate the total resistance of the circuit (1mk)
    3. The circuit below is connected The potential difference across resistor R is measured
       
       The ammeter reading and voltmeter reading are shown on the scales below
       
       
       1. Record these two readings (2mk)
          ammeter reading = .........................................................A
          voltmeter reading = .........................................................V
    4. Using the values above calculate
       1. the resistance of R, (2mks)
       2. find the total resistance of the circuit (2mks)
    5. Which two indicators guide one on when to recharge a lead acid accumulator? (2mks)
17.              
    1. Some students wish to determine the focal length of a convex lens of thickness 06cm using an optical pin and a plane mirror Figure 6 shows the experimental set up when there is no parallax between the pin and the image
       
       Fig 6
       Determine the focal length of the lens (2mks)
    2. An optician in Eldoret Hospital examined an eye of a patient and made the following observations:
       Eye too short and the focal length of the eye lens short
       1. State the eye defect the patient could be having (1mk)
       2. Use a diagram to describe how the defect could be corrected (2mks)
    3. The graph below shows the variation of 1/v and 1/u in an experiment to determine the focal length of a lens
       
       Fig 7
       1. Use the graph to determine the focal length (3mks)
       2. What is the power of the lens used? (2mks)
    4. A converging lens forms an image which is three times the object Determine the focal length of the lens if the distance between the object and the screen is 80cm (3mks)
18.                        
    1. the figure below shows a ray of light PQ incident on air-water interface The ray strikes the bottom surface at M instead of N
       
       The ray makes an angle of 40o at N and 54o at M with the horizontal
       1. Determine;
          1. the angle of incidence (1mk)
          2. the angle of refraction (1mk)
       2. Calculate the refractive index of water (2mks)
    2. The figure below shows a beam of white light incident on a glass prism A thermometer with a blackened bulb is placed as shown After some time, the thermometer reading was observed to rise steadily
       
       
       1. Why is the bulb of the thermometer blackened? (1mk)
       2. Identify the colour that forms on the screen at points P and Q (2mks)
       3. Why did the reading of the thermometer rise? (1mk)