CIE iGCSE Co-Ordinated Science P3.4 Sound Exam Style Questions Paper 3
Question
(a) Fig. 12.1 shows an electric heater used in a classroom in a school.
The air around the heater is warmed.
(i) On Fig. 12.1 draw three more arrows to show how the warmed air moves around the classroom.
One arrow has been drawn for you.
(ii) State the name of the method of thermal energy transfer you have drawn in (a)(i).
(b) The teacher in the classroom measures the temperature in the room with a thermometer.
Fig. 12.2 shows the thermometer.
(i) State the name of the temperature scale used on the thermometer.
(ii) State the name of a liquid that is used in thermometers.
(iii) State the physical property of the liquid that varies with temperature.
(c) (i) In the school an electric bell rings to show that the lesson has ended.
The bell makes sound waves that travel through the air.
Sound waves cannot travel through a vacuum.
Explain why sound cannot travel through a vacuum.
(ii) Inside the electric bell there is a solenoid.
The solenoid coil is shown in Fig. 12.3.
On Fig. 12.3, draw the pattern of the magnetic field that is produced when an electric current passes through the solenoid as shown.
▶️Answer/Explanation
Ans : 12(a)(i) arrow
across the top
then dropping down
then left to right along floor
1 mark for any one correct arrow ;
1 mark for all three arrows correct ;
12(a)(ii) convection ;
12(b)(i) celsius ;
12(b)(ii) alcohol or mercury ;
12(b)(iii) volume / density ;
12(c)(i) There is no medium (for the propagation of the sound wave) ;
12(c)(ii) at least two lines going all the way through coil ;
line curving upwards and line curving downwards ;
Question
(a) α-particles, β-particles and γ-rays are all used in hospitals to treat cancer.
Table 6.1 gives information about the nature and charge of these three radiations.
(i) Complete Table 6.1.
(ii) Place the three radiations in order of their ionising ability, from most ionising to least ionising.
(iii) State which radiation is the most penetrating.
(b) X-rays and ultrasound waves are also used in hospitals.
(i) State one use of X-rays in hospitals.
(ii) Ultrasound waves have a frequency that is too high for a human to hear.
Use your knowledge of the range of audible frequencies for a human to suggest the frequency of ultrasound waves.
(c) A doctor in the hospital uses some sanitising hand liquid. The liquid contains ethanol, which evaporates from the skin of the doctor and cools the doctor’s hands.
Explain why the evaporation of the ethanol causes the doctor’s skin to cool.
Use ideas about molecules in your answer.
▶️Answer/Explanation
Ans : 6(a)(i)
;;;
one mark for each correct row
6(a)(ii) (in order)
$\alpha$ (-particles)
β (-particles)
$\gamma$ (-rays);
6(a)(iii) $\gamma$ -rays ;
6(b)(i) scanning / imaging (tissues) inside the body ;
6(b)(ii) any value above 20 000 (Hz) ;
6(c) most energetic molecules escape ;
from surface of liquid ;
lowering the temperature of the remaining ethanol molecules ;
Question
A person climbs a mountain.
(a) The person is exposed to infrared and ultraviolet radiation from the Sun.
Infrared and ultraviolet radiation are part of the electromagnetic spectrum.
(i) Fig. 3.1 shows an incomplete electromagnetic spectrum.
On Fig. 3.1, write infrared and ultraviolet in their correct places.
(ii) Ultraviolet waves travel at 300 000 000 m / s in a vacuum.
State the speed of infrared waves in a vacuum.
(b) The person makes a loud sound and then hears an echo.
State what is meant by an echo.
(c) The person takes a photograph with a camera.
The camera contains a thin converging lens.
Fig. 3.2 shows an incomplete ray diagram for a thin converging lens forming an image.
(i) State the name of the points labelled F on Fig. 3.2.
(ii) On Fig. 3.2:
• draw a line to complete the path of ray 2
• draw the image formed
• label the image.
(d) The person drops the camera from the top of the mountain. The camera falls down the mountain.
Fig. 3.3 shows the distance–time graph for the motion of the camera over the first 6.0 s
Use Fig. 3.3 to determine the average speed of the camera over 6.0 s.
▶️Answer/Explanation
Ans : 3(a)(i)
infrared correct ;
ultraviolet correct ;
3(a)(ii) 300 000 000 (m / s) ;
3(b) the reflection of sound ;
3(c)(i) principal focus / focal point ;
3(c)(ii) horizontal line drawn from lens to intersect with ray 1 ;
inverted (labelled) arrow for image ;
3(d) total distance 180m ;
evidence of speed = distance ÷ time / 180 ÷ 6.0 ;
30 (m/ s) ;
Question
(a) A spacecraft carrying an astronaut travels 384 000 km from the Earth to the Moon in 78 hours.
Calculate the average speed of the spacecraft in km / s.
average speed = ………………………………………… km / s
(b) The mass of the astronaut on the Earth is 90 kg.
(i) Calculate the weight of the astronaut on the Earth.
The gravitational force on unit mass, g, is 10 N / kg.
weight = …………………………………………….. N
(ii) State the mass of the astronaut on the Moon.
mass = ……………………………………………. kg
(c) (i) The astronaut communicates with Earth using radio waves.
Fig. 3.1 shows an incomplete electromagnetic spectrum.
Write radio waves in the correct position in Fig. 3.1.
(ii) Explain why it is not possible for the astronaut to communicate with Earth using sound waves.
(d) The astronaut collects a lump of moon rock.
The rock contains iron-60, a radioactive isotope.
(i) State the meaning of the term isotope.
(ii) Iron-60 decays by the emission of β-particles.
Complete the sentences to describe the nature of β-particles.
β-particles are identical in nature to ………………………………… .
β-particles have a single ………………………………… charge.
▶️Answer/Explanation
Ans : 3(a) 78 hours = 78 × 3600 = 280 800 seconds ;
speed = distance / time (in any form) or 384 000 / 280 800 ;
= 1.37 (km / s) ;
3(b)(i) weight = mass × g (in any form) or 90 × 10 ;
= 900 (N) ;
3(b)(ii) 90 (kg) ;
3(c)(i) radio (waves) in right hand box ;
3(c)(ii) sound waves need a medium / sound waves do not travel through a vacuum ;
3(d)(i) atoms of the same element that have different numbers of neutrons ;
OR
atoms which have the same number of protons and different numbers of neutrons ;
OR
atoms which have the same atomic number but different mass number ;
3(d)(ii) electrons ;
negative ;
Question
(a) Table 6.1 shows the audible frequency range of five animals.
(i) State which animal in Table 6.1 can hear a sound with the highest pitch.
(ii) State which animal in Table 6.1 has the smallest audible frequency range.
(iii) State the audible frequency range for a human.
from …………………………………. Hz to …………………………………. Hz
(b) The volume of an elephant is 3.4 m3.
The average density of the elephant is 1030 kg / m3.
Calculate the mass of the elephant.
mass = ……………………………………………. kg
(c) The elephant sprays its skin with water and leaves the water to evaporate.
(i) Describe the process of evaporation in terms of water molecules.
(ii) Suggest why the elephant sprays its skin with water and leaves the water to evaporate.
(iii) During evaporation, liquid water changes state and becomes water vapour, a gas.
Complete the diagrams in Fig. 6.1 to show the arrangement of molecules in liquid water and in water vapour.
▶️Answer/Explanation
Ans : 6(a)(i) bat ;
6(a)(ii) elephant ;
6(a)(iii) 20 (Hz) to 20 000 (Hz) ;
6(b) mass = density × volume (in any form) or 1030 × 3.4 ;
= 3500 (kg) ;
6(c)(i) fastest moving molecules escape ;
from the surface of the liquid ;
6(c)(ii) evaporation has a cooling effect ;
6(c)(iii) liquid – all molecules touching random arrangement ;
gas – molecules widely separated (no more than seven shown) and random arrangement ;
Question
(a) High frequency sound waves are called ultrasound.
An ultrasound wave travels 13.5cm in 0.000090s through water.
Calculate the speed of the ultrasound wave in m/s.
speed = …………………………………………. m/s
(b) Ultrasound waves are used in hospitals to scan unborn babies.
(i) Suggest a reason why it is not safe to scan unborn babies with X-rays.
(ii) State one use for X-rays in a hospital.
(c) (i) γ-radiation is used in hospitals to kill cancerous cells.
Fig. 3.1 shows an incomplete electromagnetic spectrum.
Write γ-radiation in its correct place.
(ii) A source of γ-radiation in a hospital is technetium-99.
Technetium-99 has a half-life of 6 hours.
The source contains 1280 undecayed atoms.
Calculate how many atoms will have decayed after 12 hours.
number of decayed atoms = …………………………………………………
▶️Answer/Explanation
Ans : 3(a) evidence of 13.5 cm = 0.135 m ;
evidence of speed = distance / time (in any form) or 0.135 / 0.000090;
= 1500 (m / s) ;
3(b)(i) ionising radiation damages / kills human cells or damages DNA ;
3(b)(ii) observing broken bones etc ;
3(c)(i) ϒ – radiation on left hand side ;
3(c)(ii) 2 half lives ; (320 remain so ) 960 atoms decayed ;
Question
Bats use the reflection of sound waves to determine the position of objects.
Fig. 6.1 shows a bat, and a moth flying in front of the bat.
(a) State the name given to a reflected sound wave. (Topic – P3.4)
▶️Answer/Explanation
Echo
Explanation: An echo is the reflection of sound waves off a surface, which is how bats detect objects in their environment.
(b) Some bats are able to detect ultraviolet radiation. Ultraviolet radiation is part of the electromagnetic spectrum. (Topic – P3.3)
(i) On the incomplete electromagnetic spectrum shown in Fig. 6.2, place ultraviolet in the correct position.
▶️Answer/Explanation
Ultraviolet should be placed between X-rays and infrared.
Explanation: The electromagnetic spectrum is ordered by wavelength and frequency. Ultraviolet (UV) radiation has a shorter wavelength and higher frequency than visible light but longer wavelength and lower frequency than X-rays.
(ii) State which part of the electromagnetic spectrum has the lowest frequency.
▶️Answer/Explanation
Radio waves
Explanation: Radio waves have the longest wavelength and the lowest frequency in the electromagnetic spectrum.
(c) A bat produces a sound wave with a frequency of 200 kHz and a wavelength of 0.0016 m.
(i) Draw straight lines to link each wave term to its definition. (Topic – P3.1)
▶️Answer/Explanation
Amplitude – Maximum displacement of points on a wave
Frequency – Number of waves passing a fixed point per second
Wavelength – Distance between the peaks on consecutive waves
Explanation: Amplitude is the height of the wave, frequency is how often the wave passes a point, and wavelength is the distance between two consecutive peaks or troughs.
(ii) Explain why a human cannot hear the sound emitted by the bat. (Topic – P3.4)
▶️Answer/Explanation
Humans cannot hear sounds with frequencies above 20 kHz.
Explanation: The human hearing range is typically between 20 Hz and 20 kHz. The bat’s sound wave has a frequency of 200 kHz, which is well above the upper limit of human hearing.
(iii) The bat changes the frequency of the sound it produces from 200 kHz to 250 kHz. State what happens to the pitch of the sound. (Topic – P3.4)
▶️Answer/Explanation
The pitch increases.
Explanation: Pitch is directly related to frequency. As the frequency increases from 200 kHz to 250 kHz, the pitch of the sound also increases.
Question
(a) A car has two headlamps, connected in parallel, across a 12V battery. There is one switch in the circuit which controls both lamps.
(i) Complete the circuit diagram in Fig. 9.1 to show how the two lamps and the switch are connected to the battery.
Fig. 9.1
(ii) The current passing through each lamp is 4.0A.
The potential difference across each lamp is 12V.
Calculate the resistance of each lamp.
State the unit of your answer.
resistance = …………………….. unit ……………….
(b) The car is crossing a long bridge.
Fig. 9.2 shows a gap in the road surface in the middle of the bridge.
On a hot day the temperature of the road surface increases.
(i) State what happens to the gap as the temperature increases.
…………………………………………………………………………………………………………………….
(ii) Explain why the gap is needed.
……………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………….
(c) The driver of the car notices that the sound from the engine is louder and has a higher pitch when the car accelerates up a hill.
(i) State how the amplitude of the sound wave changes when the car accelerates up the hill.
…………………………………………………………………………………………………………………….
(ii) State how the frequency of the sound wave changes when the car accelerates up the hill.
…………………………………………………………………………………………………………………….
(iii) The car gains thermal energy as it accelerates up the hill.
State two other forms of energy gained by the car as it accelerates up the hill.
1 ……………………………………………………………………………………………………………………
2 ……………………………………………………………………………………………………………………….
▶️Answer/Explanation
Ans: 9(a)(i) all symbols correct ;
two lamps in parallel with battery ;
switch to control both lamps ;
9(a)(ii) R = V/I (in any form symbols or words) or 12/4 ;
= 3 ;
ohms / Ω ;
9(b)(i) gap is smaller/closes ;
9(b)(ii) road/bridge needs to expand on hot day/
road/bridge could be damaged by expansion ;
9(c)(i) amplitude increases ;
9(c)(ii) frequency increases ;
9(c)(iii) kinetic (energy);
gravitational potential (energy) ;
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
6. (a) (iii) The sound waves travel 80 m. The speed of sound in water is 1600 m/s. Calculate the time taken for a sound wave to travel 80 m in water.
▶️Answer/Explanation
Answer: 0.05 s
Sub-topic Code: P7.1 (Sound)
Detailed Solution: Time = distance / speed = 80 m / 1600 m/s = 0.05 s.
6. (b) (i) Describe the motion of the dolphin between time = 0 and time = 5 s in Fig. 6.2.
▶️Answer/Explanation
Answer: accelerating / speed increasing
Sub-topic Code: P1.1 (Motion)
Detailed Solution: The dolphin is accelerating, as its speed increases over time from 0 to 5 seconds.
6. (b) (ii) State the maximum speed of the dolphin as shown on the graph.
▶️Answer/Explanation
Answer: 6 m/s
Sub-topic Code: P1.1 (Motion)
Detailed Solution: The maximum speed of the dolphin, as shown on the graph, is 6 m/s.
6. (b) (iii) Calculate the distance travelled by the dolphin between time = 15 s and time = 30 s.
▶️Answer/Explanation
Answer: 45.0 m
Sub-topic Code: P1.1 (Motion)
Detailed Solution: The distance travelled is the area under the speed-time graph between 15 s and 30 s. This is a triangle with base = 15 s and height = 6 m/s. Area = 0.5 × base × height = 0.5 × 15 × 6 = 45.0 m.
6. (c) Describe the process of evaporation using ideas about particles.
▶️Answer/Explanation
Answer: fast moving / most energetic particles; escape from surface of liquid
Sub-topic Code: P4.1 (Thermal Properties)
Detailed Solution: Evaporation occurs when the most energetic particles at the surface of a liquid gain enough energy to escape into the gas phase. This leaves the remaining liquid cooler.