Mafunde Oyima - Mavuto ndi Mayankho
1. Chingwe cha mamita atatu chimamangiriridwa kumapeto kwina ndipo kumapeto kwina kumalumikizidwa ndi vibrator. Pamene vibrator ikugwedezeka, chingwecho chimapanga mafunde osasuntha , monga momwe chithunzi chili pansipa chikusonyezera.
Dziwani malo a antinode yachisanu kuchokera kumapeto okhazikika.
Yankho:
Mtunda pakati pa ma node awiri = mamita 3 / 5 = mamita 3/5.
Mtunda pakati pa mfundo yoyamba ndi mapeto okhazikika = 3/5 mamita
Mtunda pakati pa mfundo yachiwiri ndi mapeto okhazikika = 2 (mamita 3/5) = mamita 6/5
Mtunda pakati pa mfundo yachitatu ndi mapeto okhazikika = 3 (mamita 3/5) = mamita 9/5
Mtunda pakati pa mfundo yachinayi ndi mapeto okhazikika = 4 (mamita 3/5) = mamita 12/5
Mtunda pakati pa mfundo ndi mfundo zotsutsana ndi mfundo = 1/2 (mamita 3/5) = 3/10 mamita.
Mtunda pakati pa node yachisanu ndi mapeto okhazikika = mtunda pakati pa node yachinayi ndi mapeto okhazikika + mtunda pakati pa node ndi antinode = 12/5 + 3/10 = 24/10 + 3/10 = 27/10 = mamita 2.7.
2. Monga momwe chithunzi chili pansipa chikusonyezera, mbali imodzi yalumikizidwa ku vibrator ndipo mbali ina yakhazikika. Ngati kutalika kwa chingwecho ndi mamita 1.5, pezani mtunda pakati pa node yachinayi ndi vibrator.
Yankho:
Mtunda pakati pa ma node awiri = 1.5 mita / 11 = 1.5 / 11 mita.
Mtunda pakati pa node yoyamba ndi vibrator = 1.5 / 11 mamita
Mtunda pakati pa mfundo yachiwiri ndi vibrator = 2 (1.5 / 11 metres) = 3/11 metres
Mtunda pakati pa mfundo yachitatu ndi vibrator = 3 (1.5 / 11 metres) = 4.5 / 11 metres
Mtunda pakati pa node yachinayi ndi vibrator = 4 (1.5 / 11 metres) = 6/11 metres = 0.54 metres
3. Chingwe chimakhala ndi malekezero onse awiri osasinthika, zomwe zimapangitsa kuti phokoso loyambira likhale ndi mafupipafupi a 420 Hz. Dziwani phokoso lachitatu.
A. 840 Hz
B. 1260 Hz
C. 1680 Hz
D. 2940 Hz
Zodziwika:
Mafupipafupi oyambira (f 1 ) = 420 Hz
Malekezero onse awiri amakhala okhazikika.
Kufunidwa: mawu achitatu owonjezera
Yankho:
Kamvekedwe koyamba (f 2 ) = 2 f 1 = 2 (420 Hz) = 840 Hz
Kamvekedwe kachiwiri (f 3 ) = 3 f 1 = 3 (420 Hz) = 1260 Hz
Kamvekedwe kachitatu (f 4 ) = 4 f 1 = 4 (420 Hz) = 1680 Hz
Yankho lolondola ndi C.
4. Kutalika kwa kutalika kwa mawu oyamba a chingwe ndi 40 cm. Ngati liwiro la mafunde a mawu mumlengalenga ndi 340 m/s, dziwani mawu achitatu.
A. 850 Hz
B. 1600 Hz
C. 1700 Hz
D. 3200 Hz
Zodziwika:
Kutalika kwa mafunde a mawu oyamba (λ) = 40 cm = 0.4 mamita
Liwiro la mafunde a phokoso mumlengalenga (v) = mamita 340/sekondi
Kufunidwa: kuchuluka kwa mawu owonjezera achitatu
Yankho:
Pansipa pali chithunzi cha mafunde oyima pa chingwe chokhala ndi malekezero onse awiri osasinthika. Choyamba, werengerani kutalika kwa chingwe pogwiritsa ntchito kutalika kwa mafunde a overtone yoyamba. Pambuyo pake, musanawerenge kuchuluka kwa overtone yachitatu, choyamba, werengerani kutalika kwa mafunde a overtone yachitatu.
Kutalika kwa mafunde a mawu oyamba:
Kutalika kwa chingwe (L) = 2. ½ λ
Kutalika kwa chingwe (L) = λ
Kutalika kwa chingwe (L) = mamita 0.4
Kutalika kwa mafunde a mawu achitatu:
L = 2 λ
0.4 = 2 λ
λ = 0.4 / 2
λ = mamita 0.2
Kuchuluka kwa mawu owonjezera achitatu:
f = v / λ
f = 340 : 0.2
f = 1700 Hertz
Yankho lolondola ndi C.
5. Chubu chotseguka mbali zonse ziwiri chokhala ndi kutalika kwa 40 cm chimapanga kamvekedwe koyambira ka 420 Hz. Dziwani kamvekedwe kachiwiri.
A. 380 Hz
B. 460 Hz
C. 840 Hz
D. 1260 Hz
Zodziwika:
Kutalika kwa chitoliro (L) = 40 cm = 0.4 mamita
Kuchuluka kwa kamvekedwe koyambira (f 1 ) = 420 Hertz
Kufunidwa: Kuchuluka kwa mawu achiwiri (f 3 )
Yankho:
Ngati kamvekedwe koyambira (f 1 ) = 420 Hertz ndiye kuti kamvekedwe kachiwiri (f 3 ) = 3 f 1 = 3 (420 Hertz) = 1260 Hertz
Yankho lolondola ndi D.
6. Mafunde a mawu pa chubu chotsekedwa ali ndi mawonekedwe a mafunde ofanana ndi…
A. Kufalikira kwa mafunde pa chingwe
B. Kufalikira kwa mafunde pa mlengalenga
C. Kugwedeza chingwe choyimirira chomwe chili kumapeto kwake
D. Kugwedeza chingwe choyimirira chomwe chili kumapeto onse awiri
Yankho:
Chubu chotsekedwa ndi chubu chomwe chimatseguka kumapeto kwina koma chotsekedwa kwina, monga momwe chithunzi chili pamwambapa chikusonyezera.
Yankho lolondola ndi C.
Mafunso ndi mayankho 20 okhudzana ndi mafunde oyima:
1. Funso: Kodi mafunde oyima n’chiyani?
Yankho: Mafunde oyima ndi mawonekedwe a mafunde omwe amawoneka kuti sakusuntha, okhala ndi ma node ndi ma antinode, omwe amabwera chifukwa cha kusokonezeka kwa mafunde awiri omwe akuyenda mbali zosiyana.
2. Funso: Kodi ma node ndi ma antinode amasiyana bwanji?
Yankho: Ma node ndi mfundo za zero amplitude, komwe mafunde amakhalabe pamalo opumulira, pomwe ma antinode ndi mfundo za max amplitude.
3. Funso: Kodi mafunde oyima angapangidwe mu njira iliyonse?
Yankho: Mafunde oyima amatha kupanga chilichonse chomwe chimalola mafunde kufalikira, monga zingwe, mizati ya mpweya, ndi madzi.
4. Funso: Kodi kuchuluka kwa mafunde oyima kumakhudzana bwanji ndi nambala yake yogwirizana?
Yankho: Ma frequency oyambira (harmonic yoyamba) ndi ma frequency otsika kwambiri a mafunde oyima. Ma harmonics apamwamba ali ndi ma frequency omwe ndi ma integer multiple a ma frequency oyambira.
5. Funso: Kodi n’chiyani chimadziwitsa malo a ma node mu mafunde oyima?
Yankho: Ma node amapangidwa pomwe mafunde oyenda mbali zosiyana amasokonezana, ndikusokonezana.
6. Funso: Kodi mafunde oyima amapangidwa bwanji pa chingwe chokhazikika mbali zonse ziwiri?
Yankho: Pamene mafunde oyenda pansi pa chingwe akuwonekera kumapeto kokhazikika, amasokoneza mafunde omwe akubwera, ndikupanga mawonekedwe a mafunde oyima ngati ma frequency akugwirizana ndi mikhalidwe ina.
7. Funso: Kodi pali ubale wotani pakati pa kutalika kwa mafunde ndi kutalika kwa sing'anga mu mafunde oyima?
Yankho: Pa chingwe chokhazikika kumapeto onse awiri, kutalika kwa sing'anga ndi chiwerengero chokwanira cha theka la kutalika kwa mafunde oyima.
8. Funso: N’chifukwa chiyani mafunde oyima sasuntha mphamvu kudutsa pakati pa zinthu?
Yankho: Ngakhale tinthu tating'onoting'ono tomwe tili pakati timasinthasintha, mawonekedwe a mafunde onse amakhalabe osasuntha, kotero palibe mphamvu yoyendera mbali iliyonse.
9. Funso: Kodi mungaone mafunde oyima m'machubu otseguka?
Yankho: Inde, mafunde oyima amatha kupangidwa m'machubu otseguka, koma mikhalidwe ya malire imasiyana ndi machubu otsekedwa, zomwe zimakhudza malo a node ndi antinode.
10. Funso: Kodi chimachitika ndi chiyani ndi mafunde oyima pamene mphamvu ya chingwe yawonjezeka?
Yankho: Kukweza mphamvu kumawonjezera liwiro la mafunde, zomwe zingasinthe mafupipafupi ndi mawonekedwe a mafunde oyima.
11. Funso: Kodi kugwedezeka kwa mafunde kumakhudzana bwanji ndi mafunde oyima?
Yankho: Kumveka bwino kumachitika pamene mphamvu yakunja kapena kugwedezeka kukugwirizana ndi ma frequency achilengedwe a dongosolo, ndikupanga mafunde oyima omveka bwino.
12. Funso: Kodi kuchuluka kwa ma core ndi kotani?
Yankho: Ma frequency oyambira, kapena first harmonic, ndi ma frequency otsika kwambiri omwe dongosolo lingathe kuthandizira mafunde oyima.
13. Funso: Kodi mawu owonjezera amakhudzana bwanji ndi mawu ogwirizana?
Yankho: Ma Overtones ndi ma frequency apamwamba kuposa ma core frequency. Overtone yoyamba ikugwirizana ndi harmonic yachiwiri, overtone yachiwiri ndi harmonic yachitatu, ndi zina zotero.
14. Funso: N’chifukwa chiyani palibe kusamuka pa ma node?
Yankho: Pa ma node, mafunde awiri osokoneza amakhala atasiya gawo ndi 180°, zomwe zimapangitsa kuti pasakhale kusokoneza kowononga komanso kuti pasakhale kusamuka kulikonse.
15. Funso: Kodi mafunde oyima angagawidwe m'magulu?
Yankho: Mafunde oyima pa chingwe amakhala opingasa motero amakhala ndi njira yozungulira (polarization). Komabe, mumlengalenga ngati mpweya, mafunde oyima amakhala akutali ndipo sawonetsa polarization.
16. Funso: N’chifukwa chiyani zida zoimbira nyimbo zimagwiritsa ntchito mfundo ya mafunde oyima?
Yankho: Zida zoimbira nthawi zambiri zimapanga mawu mwa kupanga mafunde oyima, ndi ma harmonics osiyanasiyana omwe amapanga ma noti osiyanasiyana a nyimbo.
17. Funso: Kodi liwiro la mafunde limakhudzana bwanji ndi mafupipafupi ndi kutalika kwa mafunde oyima?
Yankho: Liwiro la mafunde (v) ndi zotsatira za ma frequency (f) ndi wavelength (λ): v = fx λ.
18. Funso: Kodi ma frequency awiri osiyana angapange mafunde oyima mu njira imodzi?
Yankho: Inde, bola ngati ma frequency akugwirizana ndi momwe mafunde oyima alili mu medium imeneyo. Ma frequency aliwonse amayimira harmonic yosiyana.
19. Funso: Kodi mafunde oyima m'machubu otsekedwa amasiyana bwanji ndi omwe ali m'machubu otseguka?
Yankho: Mu machubu otsekedwa, mbali imodzi ili ndi node pomwe mbali inayo ili ndi antinode. Mu machubu otseguka, mbali zonse ziwiri zili ndi antinode.
20. Funso: Kodi mafunde oyima angapangidwe ndi ma frequency aliwonse mu sing'anga yoperekedwa?
Yankho: Ayi, ma frequency enieni okha omwe amakwaniritsa malire a sing'anga ndi omwe amatulutsa mafunde oyima.
Kumvetsetsa mafunde oyima n'kofunika kwambiri m'magawo osiyanasiyana, kuyambira nyimbo mpaka kulumikizana, chifukwa amayimira machitidwe oyambira a mafunde pansi pa mikhalidwe inayake.
