CIE iGCSE Co-Ordinated Science P3.2.2 Refraction of light Exam Style Questions Paper 3
Question
(a) An oil tanker is carrying petroleum.
Petroleum is a non-renewable energy source.
Identify the energy sources in Table 12.1 as renewable or non-renewable by placing a tick (3) for each one in the correct column.
One has been done for you.
(b) Fig. 12.1 shows a speed–time graph for the oil tanker.
The graph is divided into sections P, Q, R and S.
(i) State a section of the graph (P, Q, R or S) when the oil tanker is travelling at a constant speed and state this speed.
section ………………………………….
speed …………………………………. m / s
(ii) State the section of the graph (P, Q, R or S) when the oil tanker has the greatest acceleration.
Explain your answer.
section ………………………………….
explanation …………………………………………………………………………
(iii) Calculate the distance travelled by the oil tanker during section P.
distance = …………………………………………….. m
(c) The captain of the oil tanker uses a telescope to look at another ship.
The telescope uses a converging lens to focus the light and form an image of the other ship.
Fig. 12.2 shows two parallel light rays passing through a convex lens.
(i) Complete the light rays in Fig. 12.2 to show how the light rays are focused by the lens at point F.
(ii) State the name of point F.
(d) Fig. 12.3 shows a wave similar to a water wave on the surface of the sea.
(i) State which letter, A, B, C, D or E, is the amplitude of the wave.
letter ………………..
(ii) State which letter, A, B, C, D or E, is the wavelength of the wave.
letter ………………..
▶️Answer/Explanation
Ans : 12(a) 
2 or 3 correct ;
4 correct ;
12(b)(i) section Q and 1 (m / s) OR
section S and 5 (m / s) ;
12(b)(ii) section R AND
greatest gradient ;
12(b)(iii) area under graph or 1/2 × 1 × 300 ;
150 (m) ;
12(c)(i) both rays meet at F ;
12(c)(ii) principal focus ;
12(d)(i) B ;
12(d)(ii) E ;
Question
(a) Fig. 9.1 shows a rocket about to be launched.
(i) The weight of the rocket is 8000000N.
When the rocket is launched, the upward force exerted by the rocket is 12000000N.
Calculate the resultant upward force on the rocket.
resultant force = …………………………………………….. N
(ii) Explain why the resultant force cannot be zero, when the rocket is launched.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(iii) The rocket travels 385000km from the Earth to the Moon in 75 hours.
Calculate the average speed of the rocket in km/ s.
speed = ………………………………………… km/s
(b) An astronaut on the rocket uses a telescope to view a star.
Fig. 9.2 shows a lens that is used in the telescope. Light rays from the star pass through the
lens and are focused at the principal focus.
(i) On Fig. 9.2, label the principal focus of the lens with the letter F.
(ii) On Fig. 9.2, draw a double headed arrow ( ↔ ) to indicate the focal length of the lens.
(iii) State the name of the process that occurs when light passes into the lens and the direction of the light changes.
…………………………………………………………………………………………………………………….
(c) The astronaut communicates with Earth using radio waves.
(i) Place radio waves in the correct place in the incomplete electromagnetic spectrum shown in Fig. 9.3.
Fig. 9.3
(ii) State which part of the electromagnetic spectrum has the greatest frequency.
…………………………………………………………………………………………………………………….
(iii) Explain why it is not possible for the astronaut to use sound waves to communicate directly with Earth.
…………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
▶️Answer/Explanation
Ans: 9(a)(i) 4 000 000 (N) ;
9(a)(ii) rocket would not, move/take off ;
9(a)(iii) conversion of 75 hours to seconds / 270 000 s ;
speed = distance ÷ time or substituted distance ÷ time ;
speed = 1.43 (km/s) ;
9(b)(i) principal focus correctly identified ;
9(b)(ii) focal length correctly identified ;
9(b)(iii) refraction ;
9(c)(i)
9(c)(ii) $\gamma$- rays ;
9(c)(iii) there is no medium / there is a vacuum ;
no particles to transfer the vibrations (preventing sound from travelling) ;
Question
(a) Fig. 12.1 shows a block of glass with a ray of light passing through it. The ray of light is passing from the air into the glass.
(i) On Fig. 12.1, label the angle of incidence with the letter i and the angle of refraction with the letter r.
(ii) On Fig. 12.1, complete the diagram to show how the ray of light continues through the glass and out into the air.
▶️Answer/Explanation
(i) The angle of incidence (i) is the angle between the incident ray and the normal (a line perpendicular to the surface of the glass at the point of incidence). The angle of refraction (r) is the angle between the refracted ray and the normal. Both angles should be labeled on the diagram.
(ii) When the ray of light enters the glass, it bends towards the normal (since glass is denser than air). When it exits the glass, it bends away from the normal. The ray should continue in a straight line parallel to the original incident ray but displaced due to refraction.
(b) Fig. 12.2 shows rays of light from an object projected onto a screen through a thin converging lens.
(i) State the name of the distance M.
(ii) Circle two words or phrases that correctly describe the image on the screen.
diminished enlarged inverted same size upright
▶️Answer/Explanation
(i) The distance M is the focal length of the lens, which is the distance from the lens to the focal point where parallel rays of light converge.
(ii) The correct words to describe the image on the screen are enlarged and inverted. A converging lens can produce an enlarged and inverted image when the object is placed between the focal point and twice the focal length from the lens.
(c) A robot is used to collect samples of radioactive material from a nuclear storage facility.
(i) Explain why the robotic vehicle is more suitable to collect the radioactive material than a human being.
(ii) Fig. 12.3 is a graph of the radioactive decay curve for a sample of the radioactive material. Use the graph in Fig. 12.3 to determine the half-life of the sample.
▶️Answer/Explanation
(i) The robotic vehicle is more suitable for collecting radioactive material because it can operate in high-radiation environments without risking human health. Robots can be designed to handle hazardous materials safely, reducing the risk of exposure to harmful radiation.
(ii) The half-life of the radioactive material can be determined from the graph by finding the time it takes for the activity to decrease to half of its initial value. For example, if the initial activity is 1000 counts/s and it decreases to 500 counts/s after 2 years, the half-life is 2 years.
(d) The robot has a d.c. motor. State two ways in which the turning effect of the current-carrying coil in the magnetic field of a d.c. motor can be increased.
▶️Answer/Explanation
Two ways to increase the turning effect (torque) of the current-carrying coil in a d.c. motor are:
- Increase the current flowing through the coil, as the force on the coil is directly proportional to the current.
- Increase the strength of the magnetic field, either by using stronger magnets or by increasing the number of turns in the coil.