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1.6.14 · D5 · HinglishOscillations & Waves

Question bank — Wave parameters — amplitude, wavelength, frequency, period, wave speed

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1.6.14 · D5 · Physics › Oscillations & Waves › Wave parameters — amplitude, wavelength, frequency, period,

True or false — justify

Right-hand side cover karo, true/false decide karo, aur reveal karne se pehle wajah bolo.

Amplitude, ek crest se trough tak ki vertical doori ke barabar hoti hai.
False. Woh doori peak-to-peak hoti hai, jo ke barabar hai. Amplitude equilibrium (middle) line se ek peak tak measure hoti hai, isliye woh us doori ki aadhi hoti hai.
Ek same string par wave ki frequency double karne se uski speed bhi double ho jaati hai.
False. Speed medium ke properties se fix hoti hai (tension aur density se). double karne par aadha ho jaata hai, taaki constant rahe.
Wavelength aur period dono "wave kitni baar repeat hoti hai" measure karte hain, isliye yeh essentially ek hi quantity hain.
False. space mein repeat hoti hai (metres), time mein repeat hota hai (seconds) — alag dimensions hain. Yeh dono sirf speed ke zariye linked hain: .
Ek given medium mein, agar , , mein se koi bhi do pata ho toh teesra hamesha nikala ja sakta hai.
True. Relation teeno ko aapas mein baandh deta hai, isliye koi bhi do milkar teesra fix kar dete hain.
Jis wave ki amplitude zyada hogi, uski wavelength bhi zyada hogi.
False. Amplitude (wiggle ki size) aur wavelength (wiggle ki spacing) independent hain. Tum ek rope ko zyada upar flick kar sakte ho bina humps ki spacing badlaye.
Agar do waves ki frequency same hai, toh unki wavelength bhi same hogi.
False. Yeh sirf tab sach hai jab woh same medium mein travel karen (same ). 500 Hz ki sound aur 500 Hz ki string wave ki wavelengths bilkul alag hongi kyunki unki speeds alag hain.
Frequency aur period inversely proportional hain, isliye aur ka graph ek straight line hoga.
False. ek reciprocal relation hai, jiska graph ek hyperbola (curve) hota hai, straight line nahi. Origin se straight line ka matlab hota , jo iska ulta hai.
Ek period mein, medium ka har particle apni starting position aur velocity par exactly wapas aa jaata hai.
True. Yahi ek poori oscillation ki definition hai — time ke baad particle ki state (position aur motion ki direction) repeat ho jaati hai.
Wave speed woh speed hai jis par medium ke particles physically move karte hain.
False. ek fixed phase wale point (jaise ek crest) ki speed hai jo medium mein travel karta hai. Particles khud apni equilibrium ke around oscillate karte hain; woh wave ke saath travel nahi karte.

Spot the error

Har line mein ek flawed statement ya step hai. Galti dhundho aur correct version batao.

"Ek buoy 1.2 m kul jhoolti hai, isliye uski amplitude 1.2 m hai."
1.2 m kul (peak-to-peak) swing hai, jo ke barabar hai. Isliye m hai, middle se ek extreme tak measure hoti hai.
"Kyunki hai, lambe period wali wave ki frequency high hogi."
Yeh ulta hai. Lamba period matlab har wobble zyada time leta hai, isliye kam wobbles per second → low frequency. Lamba ↔ chhota .
"Maine frequency badhayi, toh crest ab string par zyada tezi se travel karta hai."
Crest ki speed medium se set hoti hai aur nahi badlati. Jo actually hua woh yeh hai ki crests ek doosre ke paas aa gaye — chhota hua — jabki same raha.
" sirf sound ke liye kaam karta hai, light ke liye nahi."
Yeh relation universal hai: yeh sab waves par laagu hota hai — sound, light, water, string waves. Sirf ki value alag-alag media mein alag hoti hai.
"Wavelength, ek crest se bilkul agli trough tak ki doori hai."
Yeh sirf aadha wavelength hai. Poora wavelength crest-to-crest ya trough-to-trough hota hai — shape ka ek complete repeat.
"Speed wavelength aur period ka product hai, ."
Galat combination. Speed distance per time hoti hai: (ek period mein ek wavelength), jo ke barabar hai kyunki . Multiply karna galat units deta hai.
"Ek 2 Hz wave 2 oscillations complete karta hai, isliye uska period 2 s hai."
2 Hz ka matlab hai 2 oscillations per second, isliye har ek s leta hai, 2 s nahi.

Why questions

Reveal karne se pehle apne words mein jawab do; reasoning hi mayne rakhti hai.

Fixed medium mein frequency badhane par wavelength kyun chhoti hoti hai, speed kyun nahi badlati?
Kyunki medium ki properties se lock hai, aur phir bhi hold karna chahiye. Agar nahi badal sakta, toh badhane par compensate karne ke liye chhota hona padta hai.
Exactly ek period mein, ek crest exactly ek wavelength kyun aage badhta hai?
Ek poori oscillation () ke baad poora pattern bilkul same dikhta hai, bas ek space-repeat aage shift ho jaata hai — aur woh space-repeat hi hai. Isliye time mein aage badhna space mein shift karne ke barabar hai.
Frequency period ki reciprocal kyun hai, say, period ki double kyun nahi?
Frequency hai "cycles per second." Exactly ek period ke time mein exactly 1 cycle hota hai, isliye direct division se aata hai.
Amplitude aur wavelength ko independently choose karne ki permission kyun hai?
Amplitude ka jawab hai "wiggle kitna bada hai?" jabki wavelength ka jawab hai "wiggles kitni door-door hain?" Yeh pattern ki alag-alag features hain, isliye koi cheez ek ko doosre par dependent nahi karti.
Ek hi equation sound, light, aur water waves sab par kyun laagu hoti hai?
Kyunki yeh purely speed ki definition (distance ÷ time) se aati hai jo kisi bhi repeating travelling pattern par apply hoti hai — derivation mein kisi specific medium ki koi property assume nahi ki jaati.
Do alag observers ek wave ki frequency par disagree kyun kar sakte hain lekin medium mein uski speed par nahi?
Yeh Doppler Effect ka preview hai: relative motion crests aane ki rate (frequency) aur unki observed spacing ko badalta hai, lekin medium mein wave ki propagation speed unchanged rehti hai.

Edge cases

Boundary aur degenerate scenarios — woh jo formulas quietly assume karke chhod dete hain.

Ek wave ki wavelength kya hogi jis ki frequency zero ke paas jaaye (bahut slow wobble), fixed par?
se, jaise , wavelength bina kisi limit ke badhti jaati hai (). "Wave" ek bahut lambi, bahut dheemi disturbance mein stretch ho jaati hai.
Fixed par jab bahut bada ho jaaye toh ka kya hoga?
: crests ek doosre ke bahut paas aa jaate hain. Yahi reason hai ki Electromagnetic Spectrum ke high-frequency end par sabse chhoti wavelengths hoti hain.
Agar wave ki amplitude zero ho, toh kya wave exist karti hai?
Koi visible disturbance nahi — har particle equilibrium line par baith jaata hai, isliye dekhne ke liye kuch nahi. , , undefined ho jaate hain kyunki measure karne ke liye koi repeating shape nahi hai.
Kya period zero ho sakta hai?
Nahi. ka matlab hoga ek oscillation zero time leta hai, jo (infinite frequency) deta hai, jo physically impossible hai — ek real medium infinitely fast respond nahi kar sakta.
Kya us moment par bhi hold karta hai jab wave pehli baar shuru hoti hai (ek akela lone pulse jis ka koi repeat nahi)?
Ek lone pulse ka koi well-defined ya nahi hota kyunki kuch repeat nahi hota, phir bhi pulse medium ki speed par travel karta hai. Is relation ko aur define karne ke liye periodic wave chahiye; speed khud hamesha meaningful hoti hai.
Agar frequency fixed rahe lekin wave ek aisi medium mein jaaye jahan zyada hai, toh ka kya hoga?
Frequency source se set hoti hai aur crossing par preserve hoti hai, isliye se zyada proportionally zyada deta hai — waves faster medium mein spread out ho jaati hain.

Active recall

Recall One-line answers
  • Amplitude vs peak-to-peak? ::: Amplitude peak-to-peak swing ki aadhi hoti hai, middle line se measure ki jaati hai.
  • Fixed medium, triple hua — ka kya hoga? ::: Yeh ek tehai reh jaata hai, kyunki aur fixed hai.
  • Kya particles wave ke saath travel karte hain? ::: Nahi; woh ek jagah oscillate karte hain jabki phase pattern par travel karta hai.

Connections

  • Simple Harmonic Motion — har particle ka aage-peechhe jaana woh SHM hai jo period aur amplitude ke peeche hai.
  • Transverse and Longitudinal Waves — yahan ke saare traps dono wave types par laagu hote hain.
  • Speed of Waves on a String — "medium set karta hai" fact precisely explain hota hai.
  • The Wave Equation y(x,t) — jahan sab parameters formally combine hote hain.
  • Doppler Effect — observer-disagreement edge cases.
  • Sound Waves aur Electromagnetic Spectrum — extreme- aur extreme- ke examples.