Rongo Awendo Uriri Joint Evalution Test - 2015

NAME:……………………………………………………..INDEX NO:………………………………….

SCHOOL:………………………………………………….CANDIDATE SIGN:…………………………

DATE:………………………………………..

232/2

PHYSICS

PAPER2

July/August -2015.

Time: 2 hours

RONGO – AWENDO – URIRI JOINT EVALUTION TEST - 2015

Kenya Certificate of Secondary Examination (KCSE)

232/2

PHYSICS

PAPER2

July/August -2014.

Time: 2 hours

Instructions to candidates.

1. Write your name and index number in the spaces provided above.

2. Sign and write the date of examination in the spaces provided

3. This paper consists of TWO sections; A and B.

4. Answer all questions in sections A and B in the spaces provided in this booklet.

5. Non-programmable electronic calculators may be used.

6. Candidates should answer the questions in English.

SECTION / QUESTION / MAXIMUM SCORE / CANDIDATE’S SCORE
A / 1- 12 / 25
B / 13 / 08
14 / 10
15 / 07
16 / 10
17 / 11
18 / 09
TOTAL / 80

This paper consists of 12 printed pages.

Candidate should check the question paper to ascertain all pages are printed as indicated

And no questions are missing.

SECTION A (25 marks)

Answer all questions in this section

1.Two plane mirrors Ml and. M2 are inclined to each other and a ray of light shone horizontally on M1 as shown:

Show on the diagram the path followed by the ray until it is reflected by M2(2 marks)

2. A student set-up the two circuits in fig.A and fig B as shown below. If the bulbs and cells were

identical, state with a reason which bulb will be brighter. (2 marks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………………………………………………………………………………………………

3.James rubbed a glass rod with a cloth to give it a positive charge. His effort to charge an

aluminum rod using the same method didn’t work out. Explain this observation (1mark)

4.The figure below shows a simple d.c. motor;

(i) Name the parts labeled P and Q

p ………………………………………………………………………………….(1mark)

Q………………………………………………………………………………….(1mark)

(ii) Explain why the pole pieces are curved (1mark)

5. The figure below shows a wave travelling along a medium.

Determine the speed of the wave if the source produces 480 vibrations per minute. (3marks)

6. Jane holds a concave mirror of focal length 1M, 80cm from her face. State two characteristics of

her image in the mirror. (2marks)

7. A cell drives a current of 2.5A through a 0.8Q resistor. When the same cell is connected to a

l.4 resistor, the current that flows is 1. 6A. Find the internal resistance and e.m. f. of the cell.

(3 marks)

8. A hospital uses X-ray of wavelength lxl0-11m. Calculate the speed of X-ray if the frequency is

3x1019Hz (2 marks)

9. An iron rod placed on a bench is stroked several times using on ole of a bar magnet. Sketch a graph showing the degree of magnetization against the number of strokes on the axes below.

(2mks)

10. Below is a nuclear reaction.

(i) Identify radiation K. (1mark)

……………………………………………………………………………………………………………………………………………………………………………………………………………

(ii) Determine the value of x and y. (1mark)

11. The chart below shows an arrangement of different parts of electromagnetic spectrum:

Radio / Infra-red / Visible / A / X-Rays / Gamma Rays

Name the radiation represented by A. (1mark)

12. An electric bulb with a filament if resistance 480 Ohms is connected to a 240V mains supply.

Determine the energy dissipated in 2 minutes.(2marks)

SECTION B (55 mark)

Answer all questions in this section

13.In an experiment to find the relationship between frequency of radiation and kinetic energy of photoelectrons in a photoelectric device, the following graph was obtained.

Use the graph to answer the following questions,

a) i) Determine the threshold frequency. (1mark)

ii) Find the plank’s constant h. (3mks)

(take the charge of an electron to be 1.6 x 10-19 C)

iii) Calculate the work function of the metal in joules. (2mks)

b) The threshold frequency of sodium is 4.8 x 1014 Hz. Calculate the work function of

sodium. (Take the plank’s constant to be 6.6 x 10-34JS) 10 JS(2 marks)

14. The figure below shows an x-ray tube

(a) i) Name the elements used in making the parts labelled A and B. (2marks)

ii) Explain the use of the part labelled C.(2 marks)

iii) Explain how the x-rays are produced. (2marks)

(b) The penetrating power of x-rays is normally varied depending on the intended use.

Explain how this is done.(1mark) ………………………………………………………………………………………………………………………………………………………………………………………………………………

c) The energy of x-ray is 1.989 x 10-14joules. Given that the speed of light is 3.0 x l08m/s and plank’s constant is 6.6 x 1034jsfind the wavelength of the x-rays. (3marks)

15. The figure 8 below shows a bridge rectifier.

Figure 8

i) Define the term rectification. (1 mark)

ii) Describe how the illustrated rectifier works. (4 marks)

iii) State the modification that can be made on the arrangement to improve the quality of the

output. (1 mark)

iv) Sketch on the grid below how the improved output is displayed on a C.R.O screen.

16. In the circuit diagram below, the internal resistance, r of the battery is 1.2

Calculate:

a) The effective resistance. (2mks)

b) The current through the 10 resistor. (3 mks)

c) (i) State any two necessary conditions for total internal reflection to occur. (2mks)

(ii) Calculate the value of the critical angle, C in the figure below: (3mks)

17. (a) Explain how a charged leaf electroscope can be used to detect the presence of radiations

in an area. (2 marks)

(b) The figure below shows a Geiger Muller tube.

(i) Explain how the tube is used to count the radiations from a radioactive source.

(3 marks)

ii) Explain the function of bromine gas. (2 marks)

c) (i) State one functional advantage of Geiger Muller tube over the diffusioncloud

chamber. (1 mark)

ii) Explain how radiations are detected in the diffusion cloud chamber. (3 marks)

18. The figure below shows a conductor moving in a region of uniform magnetic field.

(i) Mark on the diagram the direction of induced current. (1 mark)

(ii) Apart from increasing the field strength, state two other ways in which the magnitude ofthe induced current can be increased. (2 marks)

b) Two coils are placed near each other as shown in the figure below:

(i) State and explain what will be observed if the switch is opened. (2 marks)

(i) Calculate the potential difference across BC (3marks)

(ii) State one assumption made in calculating the potential difference across BC. (1mark)