Q.When two waves of almost equal frequencies n1 and n2 reach at a point simultaneously, what is the time interval between successive maxima?
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Beats Frequency Analysis
The Intuition: When Two Tones "Wobble"
Imagine you're tuning a guitar. You pluck the string you're tuning, and at the same time, you play a reference note from a tuning fork. If the two notes are exactly the same pitch, you hear a single steady tone. But if they are slightly different — say one is 440 Hz and the other is 442 Hz — you don't hear two separate notes. Instead, you hear a single tone that wobbles in loudness: it gets louder, then softer, then louder again, in a slow, rhythmic pulse.
That pulse is called a beat. The phenomenon is beats.
Why does this happen? Because the two sound waves are constantly going in and out of sync. When their crests align, they add up to a louder sound (constructive interference). When a crest meets a trough, they cancel partially (destructive interference). The result is a wave whose amplitude rises and falls at a rate equal to the difference between the two original frequencies.
You don't hear the individual frequencies when they are very close. Your ear perceives the average frequency (around 441 Hz in the example), but the loudness fluctuates at the beat frequency.
The Precise Statement
Let two sound waves of slightly different frequencies f1 and f2 (with f1>f2) travel through the same medium. Their displacements at a point can be written as:
y1=Asin(2πf1t)
y2=Asin(2πf2t)
By the principle of superposition, the resultant displacement is:
y=y1+y2=A[sin(2πf1t)+sin(2πf2t)]
Using the trigonometric identity sinP+sinQ=2sin(2P+Q)cos(2P−Q), we get:
y=2Acos(2π2f1−f2t)sin(2π2f1+f2t)
This is the key equation. It describes a wave with two parts:
- The carrier wave: sin(2π2f1+f2t) — this oscillates at the average frequency favg=2f1+f2. This is the pitch you actually hear.
- The envelope: 2Acos(2π2f1−f2t) — this modulates the amplitude of the carrier. The envelope oscillates at half the difference frequency.
Beat Frequency:
fbeat=∣f1−f2∣
This is the number of loudness maxima (or minima) you hear per second.
Why ∣f1−f2∣ and not half of it? Because the cosine term goes through a full cycle (from maximum to minimum and back to maximum) when its argument changes by 2π. That happens when 2f1−f2t=1, i.e., t=f1−f22. So the time period of the envelope is Tenvelope=∣f1−f2∣2. But the loudness (intensity) goes through two maxima per envelope cycle — one at each positive peak of the cosine and one at each negative peak (since squaring the amplitude gives intensity). So the period of the beat (the time between successive loudness maxima) is half of that: Tbeat=∣f1−f2∣1. Hence, the beat frequency is fbeat=Tbeat1=∣f1−f2∣.
A common mistake is to think the beat frequency is 2∣f1−f2∣. That is the frequency of the envelope oscillation, not the beat. The ear detects two loudness peaks per envelope cycle, so the beat frequency is double the envelope frequency.
Key Conditions for Beats
- Small difference: The two frequencies must be close (typically less than about 10–15 Hz apart). If the difference is too large, the ear perceives two separate tones instead of beats.
- Comparable amplitudes: The amplitudes should be roughly equal for maximum contrast in loudness. If one is much louder, beats are still present but less noticeable.
- Same medium: The waves must overlap in the same region of space.
Why This Matters for Exams …
Concept: Beat Frequency Analysis
When two waves of nearly equal frequencies n1 and n2 superpose, they produce a phenomenon called beats. The resultant amplitude oscillates periodically between maximum and minimum values.
The beat frequency—the rate at which maxima (or minima) occur—is given by:
fbeat=∣n1−n2∣ …
When two waves of nearly equal frequency interfere, they produce beats—periodic variations in amplitude. The time between successive maxima (loud sounds) is the reciprocal of the beat frequency: ∣n1−n2∣1.
Why beats occur
When two waves of slightly different frequencies superpose, they drift in and out of phase with each other. Sometimes their crests align and reinforce (constructive interference, maximum amplitude); half a beat cycle later, a crest meets a trough and they cancel (destructive interference, minimum amplitude). This periodic rise and fall in intensity is what we hear as beats.
The mathematics reveals that the combined wave oscillates at the average frequency 2n1+n2, but its amplitude itself oscillates slowly at the beat frequency ∣n1−n2∣. Each complete cycle of the amplitude envelope—from one maximum through a minimum and back to the next maximum—takes one beat period.
Step-by-step derivation
- Write the two waves. Assume both have the same amplitude A and meet at a point. Their displacements are:
y1=Asin(2πn1t),y2=Asin(2πn2t).
- Superpose them. The resultant displacement is:
y=y1+y2=A[sin(2πn1t)+sin(2πn2t)].
- Apply the sum-to-product identity. Recall that sinC+sinD=2sin(2C+D)cos(2C−D). Here:
y=2Acos(2π2n1−n2t)sin(2π2n1+n2t).
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Identify the modulation. The sine term oscillates rapidly at the average frequency 2n1+n2 (the carrier). The cosine term oscillates slowly at frequency 2∣n1−n2∣ and acts as a time-varying amplitude envelope.
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Recognize that intensity depends on amplitude squared. The amplitude envelope is:
Aenv(t)=2A∣cos(π(n1−n2)t)∣.
The intensity (proportional to Aenv2) reaches a maximum whenever cos2(π(n1−n2)t)=1, which happens twice per cycle of the cosine—once at each peak of ∣cos∣. …
Step 1: Model the two waves meeting at the point as y1=Asin(2πn1t) and y2=Asin(2πn2t) (same amplitude, nearly equal frequencies).
Step 2: Superpose and apply the sum-to-product identity sinC+sinD=2sin(2C+D)cos(2C−D):
y=2Acos(π(n1−n2)t)sin(2π2n1+n2t).
The sine factor is a fast carrier at the average frequency; the cosine factor is a slow amplitude envelope.
Step 3: Intensity (∝ amplitude²) is maximum whenever ∣cos(π(n1−n2)t)∣=1, i.e. π(n1−n2)t=mπ for integer m, so maxima occur at t=∣n1−n2∣m. …
Showing the 12 most recent of 37 on this concept.
- TG EAPCET 2026Set eng-2026-05-09-AN1 markMCQQ.A source of sound of frequency 660 Hz and an observer are moving towards each other with speeds of 31 kmph and 23 kmph respectively. If the wind blows with a speed of 5 kmph from observer towards the source, then the frequency of the sound heard by the observer is (Speed of sound in air =340 ms−1) (A) 630 Hz (B) 660 Hz (C) 690 Hz (D) 720 Hz
›Reveal solutionSolution
The presence of wind means we must calculate the speeds of the source and observer relative to the air (the medium) before applying the Doppler effect formula. The observed frequency is 690 Hz.
Concept and Intuition
The Doppler effect describes the change in frequency of a wave for an observer moving relative to its source. For sound waves, this effect depends on the relative velocities of the source, the observer, and the medium (air) through which the sound travels.
The crucial point when wind is present is that the speed of sound (v) in the Doppler formula refers to the speed of sound relative to the medium (i.e., in still air). Similarly, the velocities of the source (vS) and the observer (vO) must also be measured relative to the medium. The wind effectively changes the velocities of the source and observer with respect to the air, even if their velocities relative to the ground remain constant.
We will first convert all given speeds to a consistent unit (m/s). Then, we will determine the velocities of the source and observer relative to the air by accounting for the wind's velocity. Finally, we will use the standard Doppler effect formula for sound, ensuring the correct signs for relative motion.
The general Doppler effect formula for sound, where v is the speed of sound in the medium, vO is the speed of the observer relative to the medium, and vS is the speed of the source relative to the medium, is:
f′=f0(v∓vSv±vO)
Here, we use +vO if the observer moves towards the source and −vO if the observer moves away. We use −vS if the source moves towards the observer and +vS if the source moves away.
Step-by-step Derivations
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Convert all speeds to meters per second (m/s):
The speed of sound in air is given as v=340 m/s.
The speeds of the source, observer, and wind are given in kmph. We convert them to m/s using the conversion factor 1 kmph=185 m/s.
- Speed of source relative to ground, vS,g=31 kmph=31×185 m/s=18155 m/s.
- Speed of observer relative to ground, vO,g=23 kmph=23×185 m/s=18115 m/s.
- Speed of wind relative to ground, vW,g=5 kmph=5×185 m/s=1825 m/s.
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Establish a coordinate system and determine velocities relative to the ground:
Let's define the direction from the source to the observer as the positive direction.
- The source is moving towards the observer, so its velocity relative to the ground is in the negative direction: VS,g=−18155 m/s.
- The observer is moving towards the source, so its velocity relative to the ground is in the positive direction: VO,g=+18115 m/s.
- The wind blows from the observer towards the source. This means the wind is blowing in the negative direction: VW,g=−1825 m/s.
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Calculate the velocities of the source and observer relative to the medium (air):
The velocity of an object relative to the medium is given by Vobject, air=Vobject, ground−Vwind, ground.
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Velocity of source relative to air (VS,air):
VS,air=VS,g−VW,g=(−18155)−(−1825)=−18155+1825=−18130 m/s=−965 m/s.
This means the source is moving at a speed of 965 m/s towards the observer relative to the air. So, vS=965 m/s.
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Velocity of observer relative to air (VO,air):
VO,air=VO,g−VW,g=(+18115)−(−1825)=+18115+1825=+18140 m/s=+970 m/s. …
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- TG EAPCET 2026Set eng-2026-05-09-FN1 markMCQQ.Two stationary sources P and Q produce sounds of equal frequency of 170 Hz. The velocity with which an observer has to move from source P towards source Q such that 8 beats are to be heard per second by the observer is (Speed of sound in air =340 ms−1) (A) 20 ms−1 (B) 16 ms−1 (C) 4 ms−1 (D) 8 ms−1
›Reveal solutionSolution
Moving away from P and toward Q, the beat count is fc2vo=8, giving vo=8 ms−1.
An observer moving with speed vo from P toward Q recedes from source P and approaches source Q. The frequencies heard:
fP=fcc−vo,fQ=fcc+vo.
Beat frequency:
fQ−fP=fc2vo=8. …
- TG EAPCET 2026Set eng-2026-05-10-FN1 markMCQQ.Two observers A and B are moving towards a stationary source of sound with speeds 0.8V0 and 0.6V0 respectively, where V0 is the speed of sound in air. The ratio of the frequencies of the sound heard by the observers A and B is (A) 4:3 (B) 9:8 (C) 1:1 (D) 2:3
›Reveal solutionSolution
The Doppler effect for a moving observer and stationary source gives f′=f0(1+V0vo). Substituting the given speeds yields a ratio of 9:8 for observer A to observer B.
The core idea here is the Doppler effect — the change in observed frequency when there is relative motion between source and observer. Since the source is stationary and both observers are moving toward it, the sound waves get "compressed" from the observer's perspective, raising the pitch. The faster the observer moves, the greater the frequency shift.
For a stationary source and a moving observer, the formula is straightforward: the observed frequency f′ equals the source frequency f0 multiplied by (1+vo/V0) when the observer moves toward the source. Here vo is the observer's speed and V0 is the speed of sound. No sign confusion — just add the ratio.
Let’s work it out step by step.
- Write the Doppler formula for a moving observer, stationary source. When the observer moves toward the source:
f′=f0(V0V0+vo)=f0(1+V0vo)
This is because the observer encounters wavefronts more frequently than a stationary observer would.
- Apply to observer A. Speed of A: vA=0.8V0.
fA=f0(1+V00.8V0)=f0(1+0.8)=1.8f0
- Apply to observer B. Speed of B: vB=0.6V0. fB=f0(1+V00.6V0)=f0(1+0.6)=1.6f0 …
- TG EAPCET 2026Set eng-2026-05-11-FN1 markMCQQ.The approximate bandwidth of frequency required to transmit music is (A) 20 kHz (B) 2800 Hz (C) 4.2 MHz (D) 100 MHz
›Reveal solutionSolution
The bandwidth needed to transmit music is determined by the highest audible frequency, which is about 20 kHz. Since bandwidth equals the highest frequency in a baseband signal, the correct choice is (A) 20 kHz.
The key concept here is bandwidth in the context of audio signals. For a signal like music, the bandwidth is simply the range of frequencies it contains. Human hearing typically spans from about 20 Hz to 20 kHz. To transmit music without significant loss of quality, the transmission system must accommodate this entire range. The lowest frequency (20 Hz) is negligible compared to the highest, so the bandwidth is essentially the highest frequency present — roughly 20 kHz.
Let’s walk through the reasoning step by step:
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Understand what bandwidth means for audio.
Bandwidth is defined as the difference between the highest and lowest frequencies in a signal. For music, the lowest audible frequency is around 20 Hz, and the highest is around 20,000 Hz (20 kHz). So the raw bandwidth is 20000−20=19980 Hz, which rounds to 20 kHz.
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Why not 2800 Hz?
2800 Hz (2.8 kHz) is roughly the bandwidth of a telephone line, which is sufficient for speech but far too narrow for music. Music contains harmonics and overtones that extend well beyond 2.8 kHz; cutting off at that frequency would make music sound muffled and dull.
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Why not 4.2 MHz or 100 MHz? …
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- TG EAPCET 2026Set eng-2026-05-11-AN1 markMCQQ.A source producing sound of frequency 990 Hz and an observer are initially at rest. If both the source and observer start moving simultaneously towards each other with accelerations 2ms−2 and 4ms−2 respectively, then the frequency of sound heard by the observer at a time of t=5s is (Speed of sound in air =340ms−1) (A) 960 Hz (B) 1080 Hz (C) 1050 Hz (D) 900 Hz
›Reveal solutionSolution
Both source and observer accelerate toward each other; at t=5s their speeds are vs=10m/s and vo=20m/s, giving f′=1080Hz.
At t=5s the speeds acquired from rest are:
- Source: vs=ast=2×5=10m/s (moving toward the observer)
- Observer: vo=aot=4×5=20m/s (moving toward the source) …
- TG EAPCET 2026Set ap-2026-05-04-FN1 markMCQQ.The frequency of a tuning fork P is 1.5% more than the frequency of tuning fork Q and the frequency of another tuning fork R is 2.5% less than the frequency of tuning fork Q. If 8 beats are produced per second when P and R are vibrated together, then the frequency of tuning fork R is (A) 203 Hz (B) 195 Hz (C) 200 Hz (D) 187 Hz
›Reveal solutionSolution
The problem involves percentage differences relative to a common reference (Q). Let Q’s frequency be f, express P and R in terms of f, use the beat frequency condition ∣fP−fR∣=8 Hz, solve for f, then find fR. The answer is 195 Hz.
The core idea is that beats per second equal the absolute difference in frequencies. When two tuning forks are sounded together, the number of beats you hear each second is simply ∣f1−f2∣. Here, P and R produce 8 beats per second, so ∣fP−fR∣=8.
Both P and R are described relative to Q. That makes Q the natural reference. Let the frequency of tuning fork Q be f Hz. Then:
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P is 1.5% more than Q. That means fP=f+1.5% of f=f+0.015f=1.015f.
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R is 2.5% less than Q. So fR=f−2.5% of f=f−0.025f=0.975f.
Now, P and R together give 8 beats per second. Since P has a higher frequency than R (because 1.015 > 0.975), the difference is fP−fR=8 Hz. No absolute value needed — we know which is larger.
So:
1.015f−0.975f=8
0.04f=8
f=0.048=200 Hz
That is the frequency of Q. The question asks for the frequency of R:
fR=0.975×200=195 Hz …
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- TG EAPCET 2026Set ap-2026-05-05-FN1 markMCQQ.A tuning fork P of frequency 384 Hz produces 6 beats per second with a tuning fork Q. When a little wax is attached to Q and again P and Q are sounded together, if the number of beats produced per second do not change, then the initial frequency of Q is (A) 390 Hz (B) 378 Hz (C) 381 Hz (D) 387 Hz
›Reveal solutionSolution
The beat frequency equals the absolute difference of the two frequencies. Adding wax lowers Q’s frequency. Since the beat count stays the same after waxing, Q’s initial frequency must have been higher than P’s, so the answer is 390 Hz.
The concept here is beats — the periodic variation in loudness when two sound waves of slightly different frequencies interfere. The beat frequency is simply ∣fP−fQ∣. The trick in this problem is to think about what happens when you add wax to a tuning fork: wax increases its mass, which lowers its natural frequency. So after waxing, Q’s frequency decreases.
Now, the beats per second remain 6 both before and after waxing. That means the absolute difference between P and Q’s frequencies stays 6 Hz, even though Q’s frequency has dropped. Let’s work through the possibilities.
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Before waxing: ∣384−fQ∣=6. So fQ could be either 384+6=390 Hz or 384−6=378 Hz. Both are possible initially.
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After waxing: Q’s frequency becomes fQ′, which is less than fQ (because wax lowers it). The beat frequency is still 6, so ∣384−fQ′∣=6.
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Test the two cases:
- If fQ=378 Hz initially, then after waxing fQ′<378 Hz. The difference ∣384−fQ′∣ would then be greater than 6 (since 384 is fixed, and Q moves further away). So beats would increase — not stay the same. This case fails. …
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- TG EAPCET 2025Set eng-2025-05-03-AN1 markMCQQ.Two tuning forks of frequencies 320 Hz and 323 Hz are vibrated together. The time interval between a maximum sound and its adjacent minimum sound heard by an observer is (A) 61 s (B) 31 s (C) 121 s (D) 91 s
›Reveal solutionSolution
When two close frequencies are sounded together, they produce beats. The time between a maximum and the adjacent minimum is half the beat period. Here the beat frequency is 3 Hz, so that time is 1/6 s.
Concept & Intuition
When two tuning forks with slightly different frequencies vibrate together, the sound you hear fluctuates in loudness. This is called beats. The loudness rises to a maximum when the two waves are in phase (constructive interference) and falls to a minimum when they are out of phase (destructive interference). The number of maxima per second is the beat frequency, which equals the absolute difference of the two frequencies. The time from one maximum to the next maximum is the beat period Tbeat=1/fbeat. But the question asks for the time from a maximum to the adjacent minimum — that’s exactly half a beat period, because the pattern goes max → min → max in one full cycle.
Step-by-step solution
- Find the beat frequency The two frequencies are f1=320 Hz and f2=323 Hz. Beat frequency:
fbeat=∣f2−f1∣=323−320=3 Hz.
- Find the beat period The beat period is the time between successive maxima:
- TG EAPCET 2025Set eng-2025-05-03-FN1 markMCQQ.Two tuning forks of frequencies 320 Hz and 323 Hz are vibrated together. The time interval between a maximum sound and its adjacent minimum sound heard by an observer is (A) 61 s (B) 31 s (C) 91 s (D) 121 s
›Reveal solutionSolution
When two close frequencies are sounded together, they produce beats. The time between a maximum and the adjacent minimum is half the beat period. Here the beat frequency is 3 Hz, so that interval is 1/6 s.
Concept & Intuition
When two tuning forks with slightly different frequencies vibrate together, the sound you hear fluctuates in loudness. These fluctuations are called beats. The beat frequency equals the absolute difference of the two source frequencies:
fbeat=∣f1−f2∣.
The beat period is the time between successive maxima (or successive minima) of loudness:
Tbeat=fbeat1.
But the question asks for the time from a maximum to the adjacent minimum. Since the loudness pattern is sinusoidal, a maximum and the next minimum are separated by exactly half a beat period.
Step-by-step solution
- Find the beat frequency
f1=320 Hz,f2=323 Hz
fbeat=∣323−320∣=3 Hz.
- Find the beat period Tbeat=fbeat1=31 s. …
- TG EAPCET 2025Set eng-2025-05-04-AN1 markMCQQ.If the frequencies of the carrier wave and message signal are 1 MHz and 28 kHz respectively, then the frequencies of the side bands are (A) 1014 kHz, 986 kHz (B) 1028 kHz, 972 kHz (C) 29 kHz, 27 kHz (D) 514 kHz, 486 kHz
›Reveal solutionSolution
In amplitude modulation, the sideband frequencies are the sum and difference of the carrier and message frequencies. With a 1 MHz carrier and a 28 kHz message, the sidebands are 1028 kHz and 972 kHz, which matches option (B).
The key idea is that amplitude modulation (AM) does not simply shift the message to the carrier frequency — it creates two copies of the message spectrum, one above and one below the carrier. These are called the upper sideband (USB) and lower sideband (LSB). Their frequencies are given by:
fUSB=fc+fmandfLSB=fc−fm
where fc is the carrier frequency and fm is the message (modulating) frequency.
Let’s work through it step by step.
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Identify the given values
Carrier frequency: fc=1 MHz=1000 kHz
Message frequency: fm=28 kHz
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Compute the upper sideband frequency
fUSB=fc+fm=1000 kHz+28 kHz=1028 kHz
- Compute the lower sideband frequency
fLSB=fc−fm=1000 kHz−28 kHz=972 kHz
- Match with the options …
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- TG EAPCET 2025Set eng-2025-05-04-FN1 markMCQQ.If the frequencies of the carrier wave and message signal are 1 MHz and 28 kHz respectively, then the frequencies of the side bands are (A) 1028 kHz, 972 kHz (B) 29 kHz, 27 kHz (C) 1014 kHz, 986 kHz (D) 514 kHz, 486 kHz
›Reveal solutionSolution
In amplitude modulation, the sideband frequencies are the sum and difference of the carrier and message frequencies. With a 1 MHz carrier and a 28 kHz message, the sidebands are 1028 kHz and 972 kHz, so option (A) is correct.
Concept & Intuition
Amplitude modulation (AM) works by varying the amplitude of a high‑frequency carrier wave in proportion to a lower‑frequency message signal. Mathematically, multiplying the carrier by the message produces new frequencies: the carrier itself plus two “sidebands” — one above the carrier (upper sideband) and one below (lower sideband). The upper sideband is at fc+fm, the lower at fc−fm. This is a direct consequence of the trigonometric identity for the product of two sinusoids.
Step‑by‑step reasoning
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Identify the given frequencies
Carrier frequency: fc=1 MHz=1000 kHz
Message (modulating) frequency: fm=28 kHz
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Recall the sideband formula
For standard AM (double‑sideband, full carrier), the sideband frequencies are:
fUSB=fc+fm,fLSB=fc−fm
- Compute the upper sideband
fUSB=1000 kHz+28 kHz=1028 kHz
- Compute the lower sideband
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- TG EAPCET 2025Set ap-2025-04-29-AN1 markMCQQ.A wire under a tension of 144 N vibrating in its fundamental mode gives 5 beats per second with a tuning fork. When the tension applied to the wire is increased to 169 N, the number of beats heard per second remains the same. The frequency of the tuning fork is (A) 125 Hz (B) 60 Hz (C) 65 Hz (D) 55 Hz
›Reveal solutionSolution
The frequency of a vibrating wire is proportional to the square root of its tension. Since the beat frequency with a tuning fork remains constant when the wire's tension increases, the tuning fork's frequency must lie between the two wire frequencies. This leads to the tuning fork's frequency being 125 Hz.
The problem describes a vibrating wire producing beats with a tuning fork under two different tensions. To solve this, we need to understand how the frequency of a vibrating wire depends on tension and what beats signify.
Concept and Intuition
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Frequency of a Vibrating Wire: For a wire vibrating in its fundamental mode, its frequency (f) is determined by its length (L), tension (T), and linear mass density (μ). The formula is:
f=2L1μT
For a specific wire, L and μ are constant. This means the frequency of the wire is directly proportional to the square root of the tension: f∝T.
Therefore, if the tension increases, the frequency of the wire will also increase.
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Beats: When two sound waves of slightly different frequencies (f1 and f2) interfere, they produce beats. The beat frequency (fbeat) is the absolute difference between their frequencies:
fbeat=∣f1−f2∣
In this problem, the two frequencies are that of the vibrating wire (fw) and the tuning fork (ft). So, fbeat=∣fw−ft∣.
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Combining the Concepts: We are given that the beat frequency remains the same (5 Hz) even when the tension in the wire is increased. Since increasing the tension increases the wire's frequency (fw), this implies a specific relationship between fw and ft.
Let fw1 be the wire's frequency at tension T1 and fw2 be the wire's frequency at tension T2.
Since T2>T1, we know fw2>fw1.
The beat frequency is 5 Hz in both cases:
∣fw1−ft∣=5
∣fw2−ft∣=5
Consider the possibilities for the initial state (fw1 relative to ft):
- Case A: fw1>ft. Then fw1−ft=5. As tension increases, fw2 increases, so fw2>fw1. If fw2 is still greater than ft, then fw2−ft>fw1−ft=5. The beat frequency would increase, which contradicts the problem statement.
- Case B: fw1<ft. Then ft−fw1=5. As tension increases, fw2 increases, so fw2>fw1. If fw2 is still less than ft, then ft−fw2<ft−fw1=5. The beat frequency would decrease, which contradicts the problem statement.
- Case C: fw1<ft and fw2>ft. This is the only scenario where the beat frequency can remain the same. The wire's frequency "crosses over" the tuning fork's frequency.
- Initially, ft−fw1=5.
- Finally, fw2−ft=5.
This means the tuning fork's frequency (ft) must lie between the two frequencies of the wire (fw1 and fw2).
Step-by-Step Solution
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Identify Given Information:
- Initial tension, T1=144 N
- Final tension, T2=169 N
- Beat frequency in both cases, fbeat=5 Hz
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Relate Wire Frequencies to Tuning Fork Frequency:
Let ft be the frequency of the tuning fork. …
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