Mafomula amagetsi ndi kukana kwamagetsi

Zitsanzo za mafunso ndi njira zoyezera ma circuit amagetsi ndi kukana kwamagetsi

Mabwalo amagetsi

1. Yang'anani chithunzi chotsatira cha magetsi. Kukula kwa mphamvu yamagetsi yomwe ikuyenda kudzera mu resistor ya 8 Ohm ndi….
A. 1,8 Ampere
B. 1,2 Ampere
C. 0,8 Ampere
D. 0,6 Ampere

Zokambirana
Amadziwika kuti:
Wotsutsa 1 (R)₁) = 12 Ω
Wotsutsa 2 (R)₂) = 8 Ω
Wotsutsa 3 (R)₃) = 10 Ω
Mphamvu yamagetsi (V) = 12 Volts
Funso: Mphamvu yamagetsi kudzera mu R₁
Yankho:

Mphamvu yamagetsi imayenda kuchokera ku mphamvu yayikulu kupita ku mphamvu yochepa. Njira ya mphamvu yamagetsi mu dera lomwe lili pamwambapa ndi yofanana ndi njira ya manja a wotchi.

Mphamvu yamagetsi yomwe ikuyenda kuchokera mu batire:
Choyamba werengani chotsutsa chosinthira (R). Pambuyo pake, werengani mphamvu yamagetsi pogwiritsa ntchito njira ya Ohm's law: V = IR kapena I = V / R pomwe V = voltage, I = current, R = resistor yosinthira.

Choletsa cholowa m'malo:
Wotsutsa R₁ ndi chotsutsa R₂ Yokonzedwa motsatizana. Chotsukira cholowa m'malo ndi:
R₁₂ =R₁ +R₂ = 12 + 8 = 20 Ω
Wotsutsa R₁₂ ndi chotsutsa R₃ Yokonzedwa motsatizana. Chotsukira cholowa m'malo ndi:
1/R = 1/R₁₂ + 1/R₃ = 1/20 + 1/10 = 1/20 + 2/20 = 3/20
R = 20/3 Ω

Mphamvu yamagetsi yomwe ikuyenda kuchokera mu batire:
I = V / R = 12 : 20/3 = 12 x 3/20 = 36/20 = 1,8 Ampere
Mphamvu yamagetsi yomwe imatuluka mu batire ndi 1,8 Amperes.

Mphamvu yamagetsi yomwe imayenda kudzera mu resistor ya 8 Ω
Vab = 12 Volt
R₁₂ = 20 Ω
R₃ = 10 Ω

Mphamvu yamagetsi yomwe imayenda kudzera mu resistor ya 10 Ω
I₃ =V_ab / R₃ = 12 Volts / 10 Ω = 1,2 Ampere
Mphamvu yamagetsi yomwe imayenda kudzera mu resistor ya 20 Ω
I₁₂ =V_ab / R₁₂ = 12 Volts / 20 Ω = 0,6 Ampere

Lamulo Loyamba la Kirchhoff limati magetsi olowa mu nthambi ndi ofanana ndi magetsi otuluka mu nthambi imeneyo. Kutengera... Lamulo loyamba la Kirchhoff Zatsimikiziridwa kuti mphamvu yamagetsi yomwe imadutsa mu resistor ya 20 Ω = mphamvu yamagetsi yomwe imadutsa mu resistor ya 12 Ω = mphamvu yamagetsi yomwe imadutsa mu resistor ya 8 Ω = 0,6 Amperes.
Yankho lolondola ndi D.

2.
Samalani ndi magetsi otsekedwa otsatirawa!
Ngati kukana komwe kuli mu gwero la magetsi kunyalanyazidwa, ndiye kuti kusiyana komwe kulipo pakati pa malekezero a chotsutsa cha 6 Ohm ndi….
A. 3 Volt
B. 2 Volt
C. 2/3 Volt
D. 1/3 Volt
Zokambirana
Amadziwika kuti:
Wotsutsa 1 = 4 Ω
Wotsutsa 2 = 3 Ω
Wotsutsa 3 = 6 Ω
Voliyumu (V) = ma volti 6
Funso: Kusiyana komwe kulipo pakati pa malekezero a resistor ya 6 Ohm
Yankho:
Chotsutsa cha 3 Ω ndi chotsutsa cha 3 Ω zimalumikizidwa pamodzi. Chotsutsa cholowa m'malo ndi:
1/R23 = 1/3 Ω + 1/6 Ω = 2/6 Ω + 1/6 Ω = 3/6 Ω
R23 = 6/3 Ω = 2 Ω

Chotsutsa cha 4 Ω ndi chotsutsa cha 2 Ω zimalumikizidwa motsatizana. Zotsutsa zolowa m'malo ndi izi:
R = 4 Ω + 2 Ω = 6 Ω

Mphamvu ya magetsi ochokera ku gwero la magetsi:
I = V / R = 6 volts / 6 ohms = 1 Ampere
Chotsutsa cha 4 Ω ndi chotsutsa cha 2 Ω zimalumikizidwa motsatizana kotero kuti malinga ndi lamulo loyamba la Kirchooff, mphamvu yamagetsi yomwe imadutsa mu chotsutsa cha 4 Ω imakhala yofanana ndi mphamvu yamagetsi yomwe imadutsa mu chotsutsa cha 2 Ω = 1 Ampere.

Kusiyana komwe kulipo pakati pa mfundo a ndi b:
V = IR = (1 Ampere)(2 Ohms) = 2 volts
Kusiyana komwe kulipo pakati pa mfundo a ndi b = kusiyana komwe kulipo pakati pa malekezero a chotsutsa cha 2 Ω = kusiyana komwe kulipo pakati pa malekezero a chotsutsa cha 3 Ω = kusiyana komwe kulipo pakati pa malekezero a chotsutsa cha 6 Ω = 2 volts.
Yankho lolondola ndi B.

Kukana kwamagetsi

3. Ma resistors atatu amagetsi, ngati akonzedwa motsatizana, mtengo wotsutsa ndi 12/11 Ohm, ngati akonzedwa motsatizana mtengo ndi 12 Ohm, ndiye kuti mtengo wa kukana kulikonse ndi...
A. 1 Ohm, 2 Ohm, 3 Ohm
B. 2 Ohm, 4 Ohm, 6 Ohm
C. 1 Ohm, 3 Ohm, 5 Ohm
D. 3 Ohm, 4 Ohm, 5 Ohm
Zokambirana
Ngati kukana kwamagetsi kwakonzedwa motsatizana, kukana kofananako kumawerengedwa pogwiritsa ntchito fomula iyi:
R = R₁ +R₂ +R₃
12 = R₁ +R₂ +R₃
Mayankho omwe angakhalepo ndi B ndi D.
Ngati kukana kwamagetsi kwakonzedwa motsatizana, kukana kofanana kumawerengedwa pogwiritsa ntchito fomula iyi: 1/R = 1/R₁ + 1/R₂ + 1/R₃.
Ngati mugwiritsa ntchito yankho B ndiye kuti:
1/R = 1/2 + 1/4 + 1/6
1/R = 6/12 + 3/12 + 2/12
1/R = 11/12
R = 12/11
Yankho lolondola ndi B.

Mtundu wa chotchinga

4. Kukana kwa tungsten ndi tin ndi 5,5 x 10 motsatana.^-8 Mita ya Ohm ndi 22 x 10^-8 Mita ya ohm. Waya wa tungsten ndi waya wa tin ndi zazitali mamita 5 iliyonse. Ngati mawaya onse awiri ali ndi mphamvu yofanana yolimbana ndipo m'mimba mwake mwa tungsten ndi 2 mm ndiye kuti m'mimba mwake mwa waya wa lead ndi... mmm
A. 2
B. 4
C. √2
D. ½ √2
Zokambirana
Amadziwika kuti:
Kukana kwa Tungsten (ρ)₁) = 5,5 x 10^-8 Mita ya Ohm
Kukana kwa tin (ρ)₂) = 22 x 10^-8 Mita ya Ohm
Utali wa waya wa tungsten (L)₁) = mamita 5
Utali wa waya wotsogolera (L)₂) = mamita 5
M'mimba mwake wa Tungsten (D)₁) = 2 mm
Utali wa Tungsten (R)₁) = 1/2 (D) = 1/2 (2 mm) = 1 mm = 1 x 10^-3 mita
Funso: M'mimba mwake wa lead (D)₂)
Yankho:
Malo ozungulira waya wa tungsten:
A₁ = π r² = π (10^-3)² = π 10^-6

Mphamvu yolimbana ndi waya wa tungsten ndi waya wa tin ndi yofanana.
R₁ =R₂
ρ₁ L₁ / TO₁ = ρ₂ L₂ / TO₂
(5,5x10^-8)(5) / π 10^-6 = (22 x 10^-8)(5) / π r²
5,5 / 10^-6 = 22 / r²
5,5 r² = 22x10 pa^-6
r² = (22 x 10^-6 / 5,5
r² = 4x10 pa^-6
r = 2 x 10^-3 mita
r = 2 mamilimita
Yankho lolondola ndi A.

Gwero la funso:

Mafunso a OSN a Sukulu ya Sekondale ya Fiziki ya Sukulu ya Sekondale