Numerical Problems Chapter 8 Waves l First Year Physics Federal Board KPK Syllabus

1. What are the wavelengths of a television station which transmits vision on 500MHz and sound on 505MHz respectively? Take speed of electromagnetic waves as 3×〖10〗^8 ms-1.
2. A person on the sea shore observes that 48 waves reach the shore in one minute. If the wavelength of the waves is 10m, then find the velocity of the waves.
3. In a ripple tank 500 waves passes through a certain point in 10s, if the speed of the wave is 3.5ms-1, then find the wavelength of the waves.
4. A string of guitar 1.3m long vibrates with 4nodes, 2 of them at the two ends. Find the wavelength and speed of the wave in the string if it vibrates at 500Hz.
5. A tension of 400N causes a 300g wire of length 1.6m to vibrate with a frequency of 40Hz. What is the wavelength of the transverse waves?
6. Compare the theoretical speeds of sound in hydrogen (M_H=2.0 g/mol,γ_H=1.4) with helium (M_He=4.0 g/mol,γ_He=1.66 & R=8334jk^(-1) mol) at 0℃.
7. The speed of sound in air at 0℃ is 332〖ms〗^(-1). What will be the speed of sound at 22℃?
8. Two tuning forks P and Q give 4 beats per second. On loading Q lightly with wax, we get 3 beats per second. What is the frequency of Q before and after loading if the frequency of P is 512Kz?
9. On a sunny day, the speed of sound in the air is 340ms-1, 2 tuning forks A & B are sounded simultaneously. The wavelength of the sounds emitted are 1.5m and 1.68m respectively. How many beats will produce per second?
10. A sound source vibrates at 200Hz and is receding from a stationary observer at 18ms-1. If the speed of sound is 331ms-1 then what frequency does the observer hear?
11. Suppose a train that has a 150Hz horn is moving at 35.0ms-1 in still air on a day when the speed of sound is 340ms-1. (a) What frequencies are observed by a stationary person at the side of tracks the as the train approaches and after it passes? (b) What frequency is observed by the train’s engineer traveling on the train?
12. The first overtone of an open organ pipe has the same frequency as the first overtone of a closed pipe 3.6m in length. What is the length of the open organ pipe?
13. What length of open pipe will produce a frequency of 1200Hz as its first overtone on a day when the speed of sound is 340ms-1?

[Khan-pti-]

For those who are confused in numerical 12. For open organ pipe u always have to tale n=2 becoz first overtone means second harmonic. And for closed organ always n=3. U can get this from the book.

[naseebullah]

Sir allah apku hamasha khoss raka ameen ameen

[The_black_widow]

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[ZeeshanAhmad-kozi]

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[TamirKhan-kq]

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[nexus_gaming_tech]

THANKS SIR YOU ARE AN OUTCLASS SIR SALUTE YOU

[amirsatti]

very helpful lecture may u live long and got success in every step of life

[hamidullahkha]

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[gammerzworld]

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[quratulain]

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[aminahaq]

Thank you soo much sir.your video helped me a lot😊

[arfahabib]

Sir numerical no.12 ma first overtune k lia n=1 uz kia h or numerical no.13 ma first overtune k lia n= 2 q uz kia?

[maheenkhan]

Sir ? Fundamental frequency / 1st hormonic / zeroth overtone same hota h or 2nd hormonic / 1st overtone same to yahan ques 12 mein "f open = V/L "
f close = 3 V/4L q nhii ??

[beautifulvideos]

sir ap jab question solve karwate hain to us mai formula lagate waqt btaya karein ke yeh formula kaise bana. i mean thora explain kiya karein formulas ko

[zainvloging]

25:20 how can n here be equal to 1 as for first overtone n is always equal to 2 ?

[Emanf_]

Numerical 6 Boht difficult method se krwaya hoa he, separately agar H and He ki velocity fond kre to asani se ho jata he...

[SudaisCreations]

sir ye numerical 12 me aap ne first overtone k liye n=1 liya... jabke numerical 13 me aap ne first overtone k lye n=2 liya... yeh zra wazih karden..

[incognito__]

Assalam o alaikum sir,
Hope you're fine.
Thanks a million for this lecture! But I still have a doubt in the last question. Sir, how n is equal to 2 for first overtone? I could be wrong but I think it is for second overtone

[sardarsabir]

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[Softskill_Academy]

Why you take n = 2 for the last problem.