Physics for IGCSE & O level - Waves And Sounds (Section 3)
1
Why can X-rays not be used for the ultrasound test?
Answer
(A)
Because it can cause cell damage to the fetus
2
Which factor does NOT affect the speed of sound?
Answer
(B)
The frequency of the sound
3
Which of the following statements is true about the relationship between frequency and wavelength?
Answer
(B)
They are inversely proportional.
4
What happens when sound is made louder?
Answer
(C)
The amplitude increases.
5
How many distinct frequencies are the human ear able to recognize?
Answer
(D)
Thousands
6
What is the effect of a change in temperature on the speed of sound?
Answer
(B)
Higher temperature, faster speed.
7
Which factor determines the pitch of a sound?
Answer
(B)
Frequency
8
What are some medical uses of ultrasound?
Answer
A
B
9
What does the speed of sound depend on?
Answer
A
B
10
What affects the speed of sound?
Answer
(C)
The medium it travels through and its temperature
11
What is the value of the frequency for the lower limit of human hearing?
Answer
(A)
20 Hz
12
If a sound wave's frequency is doubled, what happens to its speed (assuming the medium stays the same)?
Answer
(C)
The speed stays the same.
13
What is the name for the bouncing back of a wave when it meets a surface?
Answer
(B)
Reflection
14
If the speed of sound in air is 330 m/s and the frequency is 330 Hz, what is the wavelength?
Answer
(B)
1 m
15
What is an example of a longitudinal wave?
Answer
(C)
Sound waves
16
What type of wave is used in ultrasound imaging?
Answer
(B)
Longitudinal wave
17
Which of these statements about the speed of sound is true?
Answer
(B)
It is faster in solids than in liquids or gases.
18
If a piano note has the same pitch, but is played louder than a guitar note, how does its wave differ?
Answer
(C)
Greater amplitude
19
Which properties of a wave are related to the amount of energy it carries?
Answer
B
A
20
What do we call the number of complete oscillations per second?
Answer
(B)
Frequency
21
What happens when a wave meets a boundary where the medium changes?
Answer
A
B
22
The number of waves per second is called:
Answer
(C)
Frequency
23
What is an example of a transverse wave?
Answer
(B)
Light waves
24
What is the speed of light?
Answer
(B)
3.0 x 10^8 m/s
25
What is an example of a longitudinal wave?
Answer
(C)
Sound waves
26
What happens to the wave if two waves meet with a wave and an identical frequency?
Answer
(C)
Interference
27
If a pulse of ultrasound takes 0.03 seconds to travel from a boat to the sea-bed and return, and the speed of sound in water is 1400 m/s, what is the water depth?
Answer
(A)
21 m
28
What is the meaning of frequency?
Answer
(B)
The number of waves passing a point per second.
29
What unit is frequency measured in?
Answer
(B)
Hertz (Hz)
30
In what medium can sound waves travel?
Answer
A
B
C
31
How can you increase the frequency of a wave?
Answer
(B)
Decrease the wavelength.
32
What does ultrasound refer to?
Answer
(B)
Sound waves with frequencies above the range of human hearing
33
What will happen if the sound is made louder (oscillation on an oscilloscope)?
Answer
(B)
The sound will be louder.
34
What happens to the wavelength when the frequency of a wave increases (assuming the speed is constant)?
Answer
(B)
Wavelength decreases
35
Which of the following is a practical application that uses ultrasound?
Answer
(A)
Measuring the depth of a lake.
36
How is the wavelength of the ultrasound in water calculated, when frequency is 40kHz?
Answer
(A)
Speed of water/40kHz
37
Which characteristic of a sound wave is most closely related to pitch?
Answer
(B)
Frequency
38
How is the speed of a wave calculated?
Answer
(C)
Frequency × Wavelength
39
What causes the Doppler effect?
Answer
(B)
The relative motion between the source of a wave and an observer.
40
What happens to the pitch of a siren as it approaches you?
Answer
(A)
The pitch increases.
41
What is the effect of the Doppler effect?
Answer
(B)
Changing the frequency of a wave due to relative motion.
42
What properties of a wave are directly related to its energy?
Answer
B
A
43
What property of a wave is measured in meters?
Answer
(C)
Wavelength
44
Which of the following is NOT a property of waves?
Answer
(C)
Mass
45
What is the term for the 'echo' effect?
Answer
(A)
Reflection
46
What is the function of the echosounder?
Answer
(B)
To measure the depth of water using sound waves.
47
What causes the 'Doppler Effect'?
Answer
(B)
Relative motion between the source and the observer.
48
What is the unit of frequency?
Answer
(A)
Hertz (Hz)
49
If a sound wave travels from air to water, what happens to its speed?
Answer
(A)
The speed increases.
50
Which of the following is a type of wave that requires a medium?
