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What is the difference between NBS ω, NBS ω sin ω t
The former is the maximum induced electromotive force produced by cutting, and the latter is the instantaneous value
The output voltage of the power station is u = 250V, the output power is 100kW, the resistance of the transmission line is 10 Ω, the power loss of the transmission line is not more than 4%, and the user voltage is 220V. (1) draw the circuit diagram of the transformer to be installed. (2) calculate the transformation ratio of the transformer to be installed
P loss = 100000 times 0.04 = 4000
I input = P / u = 400
I wire = I transmission times N2 / N1
U loss = I wire times R
P loss = u loss multiplied by I wire
Lianlide N1 / N2 = 1 / 20
U out = u out multiplied by N1 / N2 = 5000
U out 2 = 220
So n3-n4 = 250-11
What is the effective value of the alternating voltage when a direct current with voltage U0 = 10V passes through resistance R and generates the same heat at the same time as an alternating current passing through resistance R / 2?
The same heat is generated at the same time, so the power is the same
This problem involves the power of alternating current: the heat generated by alternating current (current or voltage) in a period of time is equal to the heat generated by direct current (current or voltage) in a period of time, then the value of direct current is the effective value of alternating current
In other words, if AC is calculated by DC power formula, the effective value of AC will be obtained directly
Let U1 be the effective value of AC voltage
U0^2/R=U1^2/(R/2)
U1 is two times the root of two, U0
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