anunaad

jaise-jaise aavrutti, anunaad aavrutti ke paas pahuainchati hai, aayaam badhata jaata hai

bhautiki mein bahut se tantron (sistams) ki aisi pravrutti hoti hai ki ve kuchh aavruttiyon par bahut adhik aayaam ke saath dolan karte hain. is sthiti ko anunaad (rijonens) kehte hain. jis aavrutti par sabse adhik aayaam vaale dolan ki pravrutti paayi jaati hai, us aavrutti ko anunaad aavrutti (resonens frikvensi) kehte hain.

sabhi prakaar ke kampanon ya tarangon ke saath anunaad ki ghatna judi hui hai. arthaat yaantrik, dhvani, vidyutachumbakeeya athva kvaantam tarang falanon ke saath anunaad ho sakti hai. koi chhote aayaam ka bhi aavarti bal, jo anunaad aavrutti wala ya uske lagbhag baraabar aavrutti wala ho, us tantr mein bahut adhik aayaam ke dolan paida kar sakta hai.

anunaadi tantron ke bahut se upayog hain. inka upayog kisi vaanchhit aavrutti par kampan (dolan) paida karne ke liya kiya ja sakta hai; athva kisi jatil kampan (jismein bahut si aavruttiyon ka mishran ho; jaise radio ya TV signal) mein se kisi chuni hui aavrutti ko chhaatane (filtar karne) ke liye kiya ja sakta hai.

anunaad hone ke liye teen cheenjein jaroori hain-

1) ek vastu ya tantr - jiski koi praakrutik aavrutti ho;
2) vaahak ya kaarak bal (driving fors) - jiski aavrutti, tantr ki praakrutik aavrutti ke samaan ho;
3) is tantr mein urja nasht karne wala avayav kam se kam ho (kam daimping ho).
(gharshan, pratirodh (rejistains), shyaanata (viskaasiti) aadi kisi tantr mein urja hraas ke liye jimmedaar hote hain.)

kaanch ki nali se ghire vaayu-stambh ka kampan evam anunaad

dhvani se sambandhit anuprayogon mein, kisi vastu ki anunaad aavrutti us vastu ki praakrutik aavruti (natural frequency) ke baraabar hoti hai. yeh mahattvapoorn hai ki kisi vastu ki praakrutik aavrutti us vastu ke bhautik avayavon (physical parameters) ke maan se nirdhaarit hoti hai. bhautik avayavon se praakrutik aavrutti ke nirdhaaran ka yeh tathya bhautiki ke sabhi kshetron (yaantriki, vidyut evam chumbakatv, aadhunik bhautiki aadi) mein laagoo hota hai.

anunaadi aavrutti ke kuchh nihitaarth is prakaar hai:

1) kisi vastu ko uske praakrutik aavrutti par kampit karaana aasaan hai; doosari aavruttiyon par kampit karaana bahut kathin hai. (kabhi kisi jhoole ko usaki praakrutik aavrutti se alag aavrutti par jhulaane ki koshish keejiye; kya yeh sambhav hai?)

2) koi kampan karti hui vastu, usako kampit karaane ke liye lagaaye gaye samishr bal (complex excitation) mein se keval us aavrutti ko chun leti hai jo usaki praakrutik aavrutti ke baraabar hoti hai aur usi aavrutti par kampit hoti hai. doosari avrutiyon ko lagbhag nakaar deti hai. is prakaar yeh ek filtar ka kaarya karti hai.

3) kampan karne waali adhikaansh vastuon ke ek se adhik (multiple) anunaad aavrutiyaaain hoti hain.

jhoola:yadi jhoole ko dhakka dete samay is baat ka dhyaan rakhein ki dhakka usi antaraal par dein jo jhoole ka praakrutik aavartakaal hai, to us jhoole ka aayaam badhataa hi chala jaata hai. arthaat har baar jhoola apni madhyamaan sthiti se adhikaadhik kon banaata chala jaata hai. iske vipreet yadi uparyukt baat ka dhyaan na rakhate hue kisi anya aavrutti par dhakka diya jaaya to usaka asar bahut kam, shoonya ya nakaaraatmak ho sakta hai.

radio evam dooradarshan:radio aur TV ke andar ek tyoond paripth (tuned circuit) hota hai jiski sahaayata se kisi ek station ya chainel ko chunakar use suna ya dekha jaata hai. jab ham radio ka 'naab' ghumaate hain to vastut: is tyoond paripth ki anunaad aavrutti ko hi badal rahe hote hain. kisi samay is paripth ki anunaad aavrutti jis kisi station ya chainel ki aavrutti se mel khaati hai (matches), vah chainel hame praapt hota hai.

lejar:lejar ek vidyutachumbakeeya tarang hai. kintu iski vishesh baat yeh hai ki yeh atyanat samavarni hota hai. arthaat iske sabhi fotaanon ki aavrutti kisi ek aavrutti ke baraabar ya bahut paas hoti hai. iske saath hi sabhi kampanon ki kalaayein (phase) bhi samaan hote hain. lejar bhi kisi prakaasheeya kaiviti mein prakaasheeya anunaad ka upayog karke utpann kiya jaata hai.

kuchh anya udaaharan hain:

• sangeet yantron mein dhvani anunaad ke liye vishesh vyavastha rahati hai.
• yaantrik ghadiyon mein santulan chakr (baileins vheel) ka kampan
• kristaleeya kaanch ka gilaas jab kisi samyak aavrutti (gilaas ki praakrutik aavruti) ke sangeet ke sampark mein aata hai to choor-choor ho jaata hai.
• kisi pratyaavarti vibhv se yadi shreni-kram mein juda L-C-R joda jaata hai (jismein pratirodh R ka maan (L/C) ke vargamool se se bahut kam ho) aur srot vibhv ka aayaam niyat rakhate hue usaki aavrutti badli jaaya to is paripth mein us sthiti mein sarvaadhik dhaara bahti hai jab srot ki aavrutti, 1/(2*Pi*L*C) ke vargamool ke baraabar ho. is sthiti ko shreni anunaad (series resonance) kehte hain.

yadi kisi rekheeya dolitr (linear oscillator) ki anunaad aavrutti Ω ho aur yeh kisi ω aavrutti vaale srot se chalaaya ja raha hai to dolanon ki teevrata I nimnalikhit sameekaran se prakat hoti hai:

${\displaystyle I(\omega )\propto {\frac {\frac {\Gamma }{2}}{(\omega -\Omega )^{2}+\left({\frac {\Gamma }{2}}\right)^{2}}}.}$

ismein Γ us tantr ke daimping (damping) ki sthiti ko vyakt karta hai. ise laainavith (linewidth) kehte hain. koi tantr jitna hi daimpd hota hai, usaki laainavith utani hi adhik hoti hai. teevrata, aayaam ke varg ke anupaati hoti hai.

• Resonance - a chapter from an online textbook
• Greene, Brian, "Resonance in strings". The Elegant Universe, NOVA (PBS)
• Hyperphysics section on resonance concepts
• A short FAQ on quantum resonances
• Resonance versus resonant (usage of terms)
• Wood and Air Resonance in a Harpsichord
• Java applet demonstrating resonances on a string when the frequency of the driving force is varied
• Breaking glass with sound, including high-speed footage of glass breaking