INSTRUCTIONS TO STUDENTS
- Write your name and admission number in the spaces provided
- Answer all questions in this question paper.
- All your answers and working must be written in the spaces provided in this question paper.
- This paper consists of 13 printed pages
- All questions must be answered in English
SECTION A (25 MARKS)
Answer all the questions in this section in the spaces provided.
- State two differences between the images formed by plane mirrors and those formed by pin-hole cameras. (2 marks)
- The figure below shows a circuit that can be used to magnetize a given bar. Complete the circuit to show the direction of the current around the bar that will result the polarities shown. (1 mark)
- The figure below shows water waves formed on a ripple tank using two dippers connected to the same vibrator.
- Show alongside the figure, the resultant of the waves when they merge. (1 mark)
- Give an explanation for your answer in (i) above. (1 mark)
-
- A ray of light moves from an optically denser medium to an optically less dense medium at an angle without being totally internally reflected in the optically denser medium. Give a possible reason for this observation. (1 mk)
- Give one use of optical fibre in the field of medicine. (1 mk)
- An electromagnet is used in making an electric bell. State the reason why soft iron is preferred to steel for use as the core. (2 mks)
- State the main difference between sound waves and water waves. (1 mk)
- An electric device has a resistance of 40Ω. When connected to a 240V mains supply, it takes a current of 10A. Determine the heat energy dissipated in 1.5 minutes. (3 mks)
- Four capacitors, A, B, C and D are connected as shown below.
State the capacitors that will acquire equal amount of charge. (1 mk) - The figure below shows a highly negatively charged rod being brought slowly towards the cap of a positively charged electroscope.
It is observed that the leaf initially falls then rises afterwards. Explain the behavior of the leaf. (2 mks) - In determining the depth of an ocean, an echo sounder produces ultrasonic sound. Give a reason why ultrasound is preferred to audible sound wave. (1 mk)
- The figure below shows a stationary wave along a string.
- Label on the diagram, the nodal points N and the antinodal points, A. (1 mk)
- If the distance between an antinode and the nearest node is 1.0 x 10-3 m, determine the wavelength of the stationary wave. (2 mks)
- Eight identical cells can be arranged in series to produce a total e.m.f of 12V just like a car battery.
- State the e.m.f of one such cell in the arrangement. (1 mk)
- Why is it possible to start a car engine of a vehicle with a lead acid accumulator, but not with eight such dry cells arranged in series? (1 mk)
- State one advantage of the lead acid accumulator over an alkaline cell. (1mk)
- Supermarkets mount large convex mirrors to improve on security monitoring. Give a reason why convex mirrors are preferred over others in this application. (1 mk)
- Two identical steel pins placed to hang on the south pole of a magnet appear as shown.
Explain the appearance of the pins. (1 mk)
SECTION B (55 MARKS)
Answer all the questions in this section in the spaces provided. -
- State Snell’s Law as applied in the study of light. (1 mk)
- In an experiment to verify Snell’s law, a student obtained different values of angle of incidence and corresponding values of angle of refraction. The results obtained were used to plot the graph shown below.
- Determine the slope of the graph. (2 mks)
- State the significance of the slope in the experiment. (1 mk)
- A ray of light is observed to move from medium A to medium B as shown below.
State and explain the change in velocity of the light wave as it moves from medium A to medium B. (2 mks) - A lake seems to be 20 m shallower than its actual depth. If the refractive index of water is 1.33, determine the real depth of the lake. (2 mks)
- Briefly explain the formation of a mirage. (3 mks)
-
-
- A metallic body shaped as shown in the figure below is positively charged and insulated from the ground as shown below.
Show the charge distribution on the conductor. (1 mk) - A sharp pin connected by a wire to the dome of a van-de-Graaf generator producing positive charges. When the sharp end of the pin is brought near a candle flame, the flame is blown away from the point of the pin. Explain this observation. (2 mks)
- A metallic body shaped as shown in the figure below is positively charged and insulated from the ground as shown below.
- Two point charges are placed close but not touching each other as shown below. Draw the electronic field around them. (1 mk)
-
- Define the term capacitance and state its SI unit. (2 mks)
- A voltmeter is connected across a charged parallel plate capacitor as shown below.
Explain the observation made on its voltmeter when the distance between the plates is reduced. (2 mks)
- The figure below shows three capacitors connected in series in an electric circuit.
Show that the effective capacitanceC_T, is given by the expression. (3 mks)
1 = 1 + 1 + 1
CT C1 C2 C3
-
-
- Define the term ‘Principal focus’ in reference to a concave lens. (1 mk)
- You are provided with the following apparatus to determine the focal length of a lens.
- A biconvex lens and a lens holder
- A lit candle
- A white screen
- A metre rule
- Draw a diagram to show how you would arrange the above apparatus to determine the focal length of the lens. (2 mks)
- Describe the procedure you would follow in performing the experiment. (2 mks)
- State the two measurements that you would take. (2 mks)
- Explain how the measurements in (iii) above would be used to determine the focal length of the lens. (2 mks)
- An object placed 15 cm from a convex lens is magnified two times. Determine the focal length of the lens. (3 mks)
-
- State one advantage of connecting lamps in parallel and not in series in a house wiring. (1 mk)
- The graph below shows how the terminal voltage of a certain cell varied with the current being drawn from the cell in a laboratory experiment.
- In the space provided below, draw a circuit diagram that could be used to obtain the results represented by the graph. (1 mk)
- Write an expression relating the e.m.f, E, terminal voltage, V, current I and the internal resistance, r, for the circuit you have drawn. (1 mk)
- From the graph, determine the;
- e.m.f of the cell. (1 mk)
- Internal resistance of the cell. (3 mks)
- In the figure below, A reads 0.6 A.
Determine the:- effective resistance in the circuit. (2 mks)
- total voltage in the circuit. (1 mk)
- current in the 4Ω resistor. (1 mk)
- voltmeter reading. (2 mks)
-
- State two factors that determine the amount of heat produced by an electric current. (1mk)
- The figure below shows a circuit with a coil used to warm oil in a beaker.
- Explain how heat is produced in the coil (2mks)
- Given that the reading of the ammeter is 2.4A determine the resistance of the coil. (2 mks)
- How much heat is produced in the coil in a minute? (3mks)
Download Physics Paper 2 Questions and Answers - Kangundo Subcounty Pre Mock Exams 2021.
Tap Here to Download for 50/-
Get on WhatsApp for 50/-
Why download?
- ✔ To read offline at any time.
- ✔ To Print at your convenience
- ✔ Share Easily with Friends / Students