Physics Paper 2 Questions - Form 4 Term 2 Opener Exams 2023

QUESTIONS

1. Polarization and local action are cell defects in a dry cell. Explain how they are minimized. (2mks)
2. State the disadvantage of using a convex mirror as a driving mirror. (1mk)
3. A student holds a book at arm’s length to read. Name the defect of her vision and the lens should use to correct the defect. (2mks)
4.                            
   1. Sketch the magnetic field patterns between the poles of the magnet. (1mk)
   2. State two properties of magnetic field lines around a bar magnet. (2mks)
5. State two ways of increasing the strength of the electromagnet. (2mks)
6. The frequency of an electronic wave is 4.0 x 10⁶Hz. Determine its wavelength (take speed of light as 3.0 x 10⁸m/s). (2mks)
7. The following is a part of a radioactivity decay series. (2mks)
   
   Determine the value of:
   1. a
   2. b
8. Given that the velocity of light in water is 2.26 x 10⁸m/s and in glass 2.0 x 10⁸m/s, calculate angle E below. (3mks)
   
9. Describe an experiment that could be used to produce a pure spectrum of light from the sun. (3mks)
10. Distinguish between mechanical wave and electromagnetic waves. (2mks)
11. How can you increase the strength and intensity of x – rays from x – ray tube. (2mks)
12. Other than Temperature and wind direction state other factor that affect the speed of sound in air. (1mk)
13.                        
    1. Power station has an out up of 33kw at a potential difference of 5kv. A transformer with a primary coil of 200 turns is used to step up the voltage to a 132kv for transmission a long a grid. Assuming that there is no power losses in the transformer, calculate the,
       1. Current in the primary coil. (2mks)
       2. Number of turns of the secondary coil. (2mks)
       3. Determine the coast of using an electric iron 1500w, for a total of 30hours given that the cost of electricity per kilowatt – hour is Kshs15.00. (3mks)
    2. Figure below shows a diagram of a bicycle dynamo. Wheel A is connected by an axle to a permanent cylindrical magnet and is rotated by the bicycle tyres.
       
14.                        
    1. State what happens to bulbs X,Y and Z I the circuit when the switches are closed as follows.
       
    2. Three resistors of 2.0n, 4.0n and 6.0n are connected together in a circuit.
       1. Draw a circuit diagram to show the arrangement of the resistors, which give minimum resistance. (1mk)
       2. Determine the effective resistance. (3mks)
       3. A wire 25cm long has a diameter of 0.70mm and resistivity of 11x10^-5Rm. Calculate the resistance of the wire. (3mks)
15.                    
    1. State two properties of x – rays. (2mks)
    2. In an x – ray tube target is made of tungsten explain. (2mks)
    3. In a certain x – ray tube, the electrons are accelerated by a p.d of 12000v. Assuming all the energy goes to produce x – rays, determine the frequency of the x – rays produced (plank’s constant h = 6.62 x 10^-34 JS and an electron e = 1.6 x 10^-19C) (4mks)
    4. Give two uses of x – rays (2mks)
    5. State one danger of x – rays. (1mk)
16. The figure below shows a ray of light is incident on an equiangular prism.
    
    
    1. Calculate the angle of refraction on the face AB given that i=300 and refractive index of glass. (3mks)
    2. Using the refracted rays on the efface AB as the incident ray on the face AC. Calculate the angle of incidence and refraction (if any) on the face AC. (4mks)
17.                  
    1. Use domain theory to explain how electrical method can be used to magnetize magnetic material. (3mks)
    2. State the meaning of magnetic shield and name one of its applications. (2mks)
    3. State one use of electromagnets. (1mk)
    4. A physics student has been provided with four materials 2 magnets, a magnetic material and a non magnetic material, state how you can use one of the magners to identify the other three types of materials. (4mks)
18.                  
    1. The figure below shows a human eye with a defect.
       
       
       1. Name the defect. (1mks)
       2. State one possible cause of this defect. (1mk)
    2. A lens from an image that is four times the size of the object on a screen. If the distance between the object and the screen is 150cm, determine;
       1. State with reasons what type of lens was used. (2mks)
       2. The focal length of the lens. (3mks)