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What is the electric power of the bulb marked with "3V 3W" when passing 0.2A current?
Resistance R = 3 ^ 2 △ 3 = 3 ohm
So the power is p = I ^ 2 × r = 0.2 × 0.2 × 3 = 0.12W
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When an electric hair dryer works in a home circuit for 2 minutes, the total energy consumed by the circuit is 67200j, so the total power of the electric hair dryer should be more than 1
w＝pt p=w÷t＝67200÷120＝5600
Hair dryer is a common electrical appliance in modern families. As shown in figure a is the circuit diagram of hair dryer, and R is the heating wire
Hair dryer is a common electrical appliance in modern families. As shown in Figure 3-28, it is the circuit diagram of hair dryer. R is the heating wire and M is the motor that drives the fan to rotate. The main technical parameters of a certain type of hair dryer are shown in the table below. Insert the plug into the socket. When the switches S1 and S2 are closed at the same time, the air blown by the hair dryer is____ If the switch S1 is only closed, the air blown by the hair dryer is____ Wind. When the hair dryer blows hot air, what is the power of the heating wire_____ (the calculation process can not be omitted)
When the switches S1 and S2 are closed at the same time, the air blown by the hair dryer is__ Heat__ Wind;
If the switch S1 is only closed, the air blown by the hair dryer is__ Cold__ The wind blows
When the hair dryer blows hot air, the power of the heating wire is 880-80 = 800W
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