Published Book on Amazon
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All of IOT Starting with the Latest Raspberry Pi from Beginner to Advanced – Volume 1 |
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All of IOT Starting with the Latest Raspberry Pi from Beginner to Advanced – Volume 2 |
출판된 한글판 도서
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최신 라즈베리파이(Raspberry Pi)로 시작하는 사물인터넷(IOT)의 모든 것 – 초보에서 고급까지 (상) |
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최신 라즈베리파이(Raspberry Pi)로 시작하는 사물인터넷(IOT)의 모든 것 – 초보에서 고급까지 (하) |
Original Book Contents
25.4.6 Direct Current Power
The power of electricity is called electric power. The electric power is equal to the value of multiplying a voltage by a current. Electric power means the amount of energy consumed when a current goes through a resistance. The electric power is expressed in W (Watt).
The electric power at direct current is calculated as follows.
Electric Power = Voltage × Current ( P = VI )
Then, since V = I R in the Ohm's law, substituting this into the equation above, the electric power can be expressed as follows. Here, we can calculate the electric power with the current and the resistance.
P = VI = (I R) x I = I2 x R [W]
And since I = V / R, the electric power can also be expressed as follows. Here, we can to calculate the electric power with the voltage and the resistance.
P = VI = V x (V / R) = V2 / R [W]