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