25 Lub zog fais fab - teeb meem thiab kev daws teeb meem
1. Siv lub teeb hluav taws xob 220 V – 5 A rau 30 feeb. Nws xav tau zog npaum li cas?
Tshuaj:
voltage (V) = 220 Volt
Hluav taws xob tam sim no (Kuv) = 5 Amperes
Lub Sijhawm (t) = 30 feeb = 30 x 60 vib nas this = 1800 vib nas this
Electric hwj chim (P) :
P = VI = (220 Volt) (5 Ampere) = 1100 Volt Ampere = 1100 Watt = 1100 Joule / thib ob
Lub zog hluav taws xob = Lub zog hluav taws xob x lub sijhawm = (1100 Joules/ob)(1800 vib nas this)
Lub zog hluav taws xob = 1,980,000 Joules = 1,980 kiloJoules
2. Siv lub hlau soldering 220 V – 60 W rau 4 feeb. Nws xav tau zog npaum li cas.
Paub:
Lub zog (P) = 60 Watts = 60 Joules/ob
Lub zog hluav taws xob (V) = 220 Volt
Lub Sijhawm (t) = 4 feeb = 4 x 60 vib nas this = 240 vib nas this
SE pob: Electric hwj chim
Tshuaj:
220 Volt - 60 Watt txhais tau tias lub tshuab hluav taws xob ua haujlwm zoo yog tias qhov sib txawv lossis qhov hluav taws xob yog 220 volts thiab muaj lub zog ntawm 60 Watt = 60 Joules / vib nas this, txhais tau tias lub tshuab hluav taws xob siv lub zog ntawm 60 Joules ib vib nas this.
Lub zog hluav taws xob = lub zog hluav taws xob x lub sijhawm = (60 Joules/ob)(240 vib nas this) = 14,400 Joules.
3. Lub zog uas lub hlau siv rau 1 feeb yog 33 kJ, ntawm qhov hluav taws xob ntawm 220 volts. Lub zog tam sim no loj npaum li cas hauv lub hlau.
Paub:
Lub sijhawm sib nrug (t) = 1 feeb = 60 vib nas this
Zog (W) = 33 kiloJoules = 33,000 Joules
Lub zog hluav taws xob (V) = 220 Volt
Xav tau: Tam sim no hluav taws xob (Kuv)
Tshuaj:
Lub zog hluav taws xob yog lub zog hluav taws xob siv rau lub sijhawm tshwj xeeb.
P = W / t = 33,000 Joules / 60 vib nas this
P = 550 Watts
Tam sim no hluav taws xob:
Kuv = P / V = 550 / 220 = 2.5 Amperes
4. Ib tug neeg saib TV nruab nrab 6 teev hauv ib hnub. Lub TV txuas nrog lub zog hluav taws xob 220 Volt kom lub zog hluav taws xob ntws los ntawm TV yog 0.5 Amperes. Yog tias lub tuam txhab hluav taws xob them $ 0.092 rau ib kWh, ces tus nqi siv hluav taws xob rau TV rau 1 hlis (30 hnub) yog ...
Paub:
Lub sijhawm sib nrug = 6 teev x 30 = 180 teev
Lub zog hluav taws xob (V) = 220 Volt
Tam sim no hluav taws xob (I) = 0.5 Ampere
Xav tau: Tus nqi ib hlis
Tshuaj:
Lub zog ntawm TV:
P = VI = (220 Volt) (0.5 Ampere) = 110 Volt Ampere = 110 Watt
Lub zog hluav taws xob = lub zog hluav taws xob x lub sijhawm
Lub zog hluav taws xob ntawm TV = 110 Watt x 180 teev = 19800 Watt teev = 19.8 kilo Watt teev = 19.8 kilo Watt teev = 19.8 kWh
Tus nqi siv hluav taws xob rau TV rau 1 lub hlis:
19.8 kWh x $0.092/kWh = $1.8216
5. Hauv ib lub tsev muaj 4 lub teeb 20 Watt, 2 lub teeb 10 Watt, 3 lub teeb 40 Watt, siv 5 teev txhua hnub. Yog tias lub tuam txhab hluav taws xob them nqi yog 0.092 ib kWh, ces tus nqi siv hluav taws xob rau 1 hlis (30 hnub) yog ....
Paub:
4 lub teeb 20 Watts = 4 x 20 Watts = 80 Watts
2 lub teeb 10 Watts = 2 x 10 Watts = 20 Watts
3 lub teeb 40 Watts = 3 x 40 Watts = 120 Watts
Tag nrho lub zog (W) = 80 Watts + 20 Watts + 120 Watts = 220 Watts
Lub sijhawm luv (t) = 5 teev x 30 = 150 teev
Xav tau: Tus nqi siv hluav taws xob rau 1 lub hlis (30 hnub)
Tshuaj:
Lub zog hluav taws xob = lub zog hluav taws xob x lub sijhawm = 220 Watt x 150 teev = 33,000 Watt teev = 33 kilo Watt teev = 33 kilo Watt teev = 33 kWh
Tus nqi siv hluav taws xob rau 1 lub hlis (30 hnub)
(33 kWh)(0.092/kWh) = $3.036
6. Ib lub voj voog muaj qhov tsis kam ntawm \(5\Omega\) thiab tam sim no ntawm \(2A\). Nrhiav lub zog hluav taws xob.
Kev daws teeb meem: \( P = IV = 2A \times 5\Omega = 10W \)
7. Ib lub roj teeb \(10V\) txuas nrog lub resistor \(2\Omega\). Xam qhov tam sim no.
Kev daws teeb meem: \( Kuv = \frac{V}{R} = \frac{10V}{2\Omega} = 5A \)
8. Ib lub teeb uas muaj zog 60W ua haujlwm ntawm lub zog 120V. Nrhiav qhov tsis kam.
Kev daws teeb meem: \( R = \frac{V^2}{P} = \frac{120^2}{60} = 240\Omega \)
9. Xam lub zog uas lub teeb \(100W\) siv rau hauv \(2\) teev.
Kev daws teeb meem: \( E = Pt = 100W \times 2h = 200Wh = 0.2kWh \)
10. Muaj lub capacitor \(20\mu F\) raug them rau \(50V\). Nrhiav lub zog khaws cia.
Kev daws teeb meem: \( E = \frac{1}{2} CV^2 = \frac{1}{2} \times 20 \times 10^{-6}F \times 50^2 = 25mJ \)
11. Txheeb xyuas qhov tam sim no hauv lub inductor \(10mH\) thaum qhov hloov pauv ntawm tam sim no yog \(5A/s\).
Kev daws teeb meem: \( V = L\frac{di}{dt} = 10 \times 10^{-3}H \times 5A/s = 50mV \)
12. Nrhiav qhov poob fais fab hauv txoj kab xa hluav taws xob uas muaj qhov tsis kam ntawm \(8\Omega\) thiab tam sim no ntawm \(3A\).
Kev daws teeb meem: \( P = I^2R = 3^2 \times 8\Omega = 72W \)
13. Ib lub transformer muaj lub zog hluav taws xob thawj zaug yog \(120V\) thiab lub zog hluav taws xob thib ob yog \(240V\). Yog tias lub zog hluav taws xob thawj zaug yog \(2A\), nrhiav lub zog hluav taws xob thib ob.
Kev daws teeb meem: Tam sim no theem ob = \( \frac{{\text{{Primary voltage}}}}}{{\text{{Secondary voltage}}}}} \times \text{{Primary current}} = \frac{{120V}}{{240V}} \times 2A = 1A \)
14. Xam qhov reactance ntawm lub inductor \(50Hz\), \(0.2H\).
Kev daws teeb meem: \(
15. Nrhiav tag nrho lub peev xwm ntawm peb lub capacitors \(10\mu F\) uas txuas ua ke.
Kev daws teeb meem: \( \frac{1}{{C_{\text{{total}}}} = \frac{1}{{C_1}} + \frac{1}{{C_2}} + \frac{1}{{C_3}} = \frac{1}{10} + \frac{1}{10} + \frac{1}{10} = \frac{3}{10}, C_{\text{{total}}} = \frac{10}{3} \mu F \approx 3.33\mu F \)
16. Ib lub supercapacitor \(0.1F\) raug them rau \(5V\). Nrhiav lub zog khaws cia.
Kev daws teeb meem: \( E = \frac{1}{2} CV^2 = \frac{1}{2} \times 0.1 \times 5^2 = 1.25J \)
17. Xam qhov fais fab ntawm lub voj voog uas muaj lub zog tiag tiag ntawm \(60W\) thiab lub zog pom tseeb ntawm \(75VA\).
Kev daws teeb meem: Lub zog fais fab = \( \frac{{\text{{Lub zog tiag tiag}}}}{{\text{{Lub zog pom tseeb}}}} = \frac{{60W}}{{75VA}} \approx 0.8 \)
18. Nrhiav qhov sib npaug ntawm ob lub resistors \(4\Omega\) uas sib txuas ua ke.
Kev daws teeb meem: \( \frac{1}{{R_{\text{{eq}}}}} = \frac{1}{{R_1}} + \frac{1}{{R_2}} = \frac{1}{4} + \frac{1}{4} = \frac{1}{2}, R_{\text{{eq}}} = 2\Omega \)
19. Txheeb xyuas qhov impedance ntawm lub voj voog uas muaj qhov tsis kam ntawm \(5\Omega\) thiab qhov reactance ntawm \(12\Omega\).
Kev daws teeb meem: Z = R^2 + X^2 = 5^2 + 12^2} \kwv yees li 13.34 \Omega
15. Xam tus nqi RMS ntawm lub zog hluav taws xob sinusoidal nrog tus nqi siab tshaj plaws ntawm \(120V\).
Kev daws teeb meem: \( V_{\text{{RMS}}} = \frac{{V_{\text{{peak}}}}}{\sqrt{2}} \approx 84.85V \)
16. Nrhiav lub zog uas ploj mus hauv lub resistor \(5\Omega\) nrog lub zog tam sim no ntawm \(4A\).
Kev daws teeb meem: \( P = I^2R = 4^2 \times 5\Omega = 80W \)
17. Xam qhov zaus ntawm lub inductor \(25mH\) nrog lub reactance ntawm \(50\Omega\).
Kev daws teeb meem: \( f = \frac{{X_L}}{{2\pi L}} = \frac{50}{{2\pi \times 25 \times 10^{-3}}} \approx 31.83Hz \)
18. Txheeb xyuas qhov tam sim no hauv lub resistor \(20\Omega\) nrog lub zog \(100V\).
Kev daws teeb meem: \( Kuv = \frac{V}{R} = \frac{100V}{20\Omega} = 5A \)
19. Nrhiav tag nrho cov inductance ntawm ob lub inductors \(10mH\) uas txuas ua ke.
Kev daws teeb meem: \( \frac{1}{{L_{\text{{total}}}}} = \frac{1}{{L_1}} + \frac{1}{{L_2}} = \frac{1}{10} + \frac{1}{10} = \frac{1}{5}, L_{\text{{total}}} = 5mH \)
20. Xam lub zog uas lub hlau \(1500W\) siv rau \(0.5\) teev.
Kev daws teeb meem: \( E = Pt = 1500W \times 0.5h = 750Wh = 0.75kWh \)
