which of the following is NOT correct? i. the pitch of a sound note depends on the frequency of vibrations. ii. the intensity of a sound note is proportional to the amplitude of vibrations. iii. beats are produced by two sources of sound because one wave is travelling faster than the other. iv. when two sources of sound of frequencies 500Hz and 502Hz are sounded together, a beat frequency of 2Hz is observed. v. the first harmonic of a tone have double the frequency of the fundamental note.
i and ii
ii and iii
i and iii
iii and iv
iv and v
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There is no answer, because the only option that is not correct is iii and v
Because the "beats are produced by two sources of sound because one wave is travelling faster than the other" is NOT correct.
Beats are produced by two sources of sound when they have slightly different frequencies, and the sound waves interfere with each other constructively and destructively. This creates an oscillating pattern of sound intensity that gives rise to the sensation of beats.
The statement i. "the pitch of a sound note depends on the frequency of vibrations" is correct.
The pitch of a sound is determined by the frequency of the sound waves, with higher frequencies corresponding to higher pitches and lower frequencies corresponding to lower pitches.
The statement ii. "the intensity of a sound note is proportional to the amplitude of vibrations" is also correct.
The intensity of a sound is determined by the square of the amplitude of the sound waves, with larger amplitudes corresponding to louder sounds.
The statement iv. "when two sources of sound of frequencies 500Hz and 502Hz are sounded together, a beat frequency of 2Hz is observed" is also correct.
When two sound waves of slightly different frequencies are played simultaneously, they produce a beat frequency that is equal to the difference between their frequencies. In this case, the difference between 502Hz and 500Hz is 2Hz, so a beat frequency of 2Hz would be observed.
The statement v. "the first harmonic of a tone has double the frequency of the fundamental note" is NOT correct.
The first harmonic of a tone (also called the fundamental frequency) has the same frequency as the fundamental note, not double the frequency. The second harmonic (twice the frequency of the fundamental), third harmonic (three times the frequency of the fundamental), and so on, all have frequencies that are integer multiples of the fundamental frequency.
I is correct
II . . . Well,intensity and loudness are not exactly the same
III is not correct
IV is correct
V depends on the instrument producing the note
I chose B
i. Pitch depends on frequency → 
Correct
(Higher frequency = higher pitch)
ii. Intensity ∝ amplitude → 
Incorrect
(Intensity ∝ amplitude²)
iii. Beats due to different speeds → Incorrect
(Beats are due to difference in frequencies, not speed)
iv. Beat frequency = 2 Hz (502 − 500) → Correct
v. First harmonic = double frequency → Incorrect
(First harmonic = fundamental; double frequency is second harmonic)
Correct Answer: B (ii and iii)
Let's analyze each statement carefully:
1. (i) The pitch of a sound note depends on the frequency of vibrations.
Correct: Pitch is directly related to frequency; higher frequency means a higher pitch.
2. (ii) The intensity of a sound note is proportional to the amplitude of vibrations.
Incorrect: Intensity is actually proportional to the square of the amplitude ().
3. (iii) Beats are produced by two sources of sound because one wave is traveling faster than the other.
Incorrect: Beats occur due to the interference of two waves with slightly different frequencies, not because one travels faster than the other.
4. (iv) When two sources of sound of frequencies 500 Hz and 502 Hz are sounded together, a beat frequency of 2 Hz is observed.
Correct: Beat frequency is given by Hz.
5. (v) The first harmonic of a tone has double the frequency of the fundamental note.
Incorrect: The first harmonic is the fundamental frequency. The second harmonic is double the fundamental frequency.
Now, let’s check the answer choices:
(ii) is incorrect (intensity is proportional to amplitude squared).
(iii) is incorrect (beats are due to interference, not wave speed differences).
(v) is incorrect (first harmonic is the fundamental, not double).
Thus, the incorrect statements are (ii), (iii), and (v). The correct answer is B (ii and iii).
The incorrect options are:
- **iii. Beats are produced by two sources of sound because one wave is travelling faster than the other** (incorrect).
- **v. The first harmonic of a tone has double the frequency of the fundamental note** (incorrect, as the first harmonic is the fundamental frequency).
So the correct answer is:
**C. iii and v**.
Thank you for your patience!
Different answer, different explanation😔🥴
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the ans is actually II AND III
BECAUSE THE INTENSITY IS DIRECTLY PROPORTIONAL TO THE SQUARE OF ITS AMPLITUDE NOT JUST THE AMLPITUDE
