Physics for IGCSE & O level - Waves And Sounds (Section 5)
1
If ultrasound pulses take 0.03 s to travel from the boat to the seabed and return, how deep is the water under the boat, assuming the speed of sound in water is 1400 m/s?
Απάντηση
(A)
21 m
2
In metal testing, what does the flaw look like on an oscilloscope?
Απάντηση
(B)
Two reflected pulses
3
What happens to the frequency when a sound source moves towards you?
Απάντηση
(B)
The frequency increases.
4
Which of these are examples of wave interference?
Απάντηση
A
C
5
If a pulse of ultrasound takes 0.1 s to travel to the sea-bed and return, and the speed of sound in water is 1400 m/s, what is the depth of the water?
Απάντηση
(B)
70 m
6
What is the role of an echo-sounder?
Απάντηση
(D)
All of the above
7
What is the difference between transverse and longitudinal waves?
Απάντηση
(B)
Longitudinal waves are always in the same direction, while transverse waves move perpendicular
8
What is the range of frequencies humans can hear?
Απάντηση
(B)
20 Hz - 20 kHz
9
The speed of sound depends on:
Απάντηση
(C)
The medium it travels through
10
What is the Doppler effect?
Απάντηση
(B)
The change in frequency of a wave due to the motion of the source or observer.
11
Which wave effect explains why you can sometimes hear a sound even when you can't see its source?
Απάντηση
(C)
Diffraction
12
What is being refered to when mentioning the 'quality' of a sound?
Απάντηση
(C)
The timbre
13
How are energy and amplitude of a wave related?
Απάντηση
(A)
Energy is proportional to amplitude.
14
How does the amplitude of a sound wave affect the loudness of the sound?
Απάντηση
(C)
Higher amplitude, higher loudness
15
What is the range of human hearing in terms of frequency?
Απάντηση
(B)
20 Hz to 20 kHz
16
What are compressions and rarefactions characteristics of?
Απάντηση
(C)
Longitudinal waves
17
What does the amplitude of a sound wave relate to?
Απάντηση
(D)
The loudness of the sound
18
What is the relationship between the period and frequency of a wave?
Απάντηση
(B)
They are inversely proportional.
19
What is a 'rarefaction' in a sound wave?
Απάντηση
(B)
A region where particles are spread out
20
What type of wave is represented by a Slinky being compressed and then stretched?
Απάντηση
(B)
Longitudinal Wave
21
What is the name of the effect where the observed frequency of a wave changes due to the motion of the source or the observer?
Απάντηση
(D)
Doppler Effect
22
Which of the following is a characteristic of longitudinal waves?
Απάντηση
(B)
They require a medium to travel.
23
What is the unit for measuring the speed of sound?
Απάντηση
(C)
Meters per second
24
What do musical instruments produce?
Απάντηση
(A)
Complex waves
25
In the context of medical applications, why is ultrasound often preferred over X-rays?
Απάντηση
(B)
Ultrasound is safer because X-rays can cause cell damage
26
What are the two main types of waves?
Απάντηση
(C)
Transverse and longitudinal
27
What is an example of a medical use of ultrasound?
Απάντηση
(B)
Breaking kidney stones
28
What is the relationship between the period and the frequency?
Απάντηση
(B)
Inversely Proportional
29
What is the role of the ultrasound transmitter/detector in the womb scanning process?
Απάντηση
(A)
To send ultrasound pulses and receive reflections
30
Which of the following is an example of reflection?
Απάντηση
(B)
An echo
31
Which of these options can be cleaned with ultrasound?
Απάντηση
(D)
All of the above
32
What type of wave is produced by a slinky toy when pushed and pulled?
Απάντηση
(B)
Longitudinal wave
33
How does the wavelength change when the frequency increases, assuming the speed of the wave remains constant?
Απάντηση
(B)
The wavelength decreases.
34
When does refraction of a wave occur?
Απάντηση
(C)
When a wave passes from one medium to another and changes speed
35
What is the relationship between speed, frequency, and wavelength?
Απάντηση
(C)
Speed = Frequency x Wavelength
36
What type of wave does light represent?
Απάντηση
(C)
Transverse wave
37
What happens to the direction of the waves when they encounter a vertical surface?
Απάντηση
(A)
They are reflected
38
How is the period of a wave related to its frequency?
Απάντηση
(B)
Period = 1 / frequency
39
What is the term for the distance between two successive crests or troughs of a wave?
Απάντηση
(C)
Wavelength
40
In which medium do sound waves travel the fastest?
Απάντηση
(D)
Solids
41
In a transverse wave, how do the oscillations move in relation to the direction of travel?
Απάντηση
(C)
Perpendicular
42
What is ultrasound?
Απάντηση
(C)
Sounds above the range of human hearing
43
What type of wave is created when you hit the water with a stick?
Απάντηση
(B)
Transverse waves
44
What happens when a wave passes through a small gap (diffraction)?
Απάντηση
(B)
The wave bends and spreads out.
45
What happens to the waves when they pass into a shallower water area?
Απάντηση
(A)
They change direction
46
What affects the speed of sound?
Απάντηση
A
B
C
47
In the context of waves, what does 'speed' refer to?
