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As shown in the figure, the specification of the electric iron is "220 V, 40 W". When s is closed, the electric iron works normally; when s is disconnected, the electric iron is in the preheating state. In order to make the power of the electric iron during preheating only 1 / 4 of the rated power, ask: (1) what kind of resistance should be selected? (2) how much electric power is consumed by the whole circuit during preheating
There's no picture, but you can probably guess
(1) For pure resistance elements such as electric soldering iron, its power is proportional to the square of the voltage at both ends. If the power is 1 / 4 of the rated power, the voltage at both ends is half of 220 V, that is 110 v. according to the law of partial voltage, the resistance value in series with electric soldering iron is the same as that of electric soldering iron, which is 220 V divided by 40 W
(2) The power of resistance and electric iron is 10W, and the total power is 20W
After a "220 V & nbsp; 40 W" electric iron is connected to a certain circuit, if the measured voltage at both ends is 110 V, then the actual power of the lamp is ()
A. 10WB. 20WC. 40WD. 80W
It is known that the rated voltage of the electric iron is 220 V, the rated power is 40 W, the resistance of the electric iron is: r = U2, P = (220 V) 240 w = 1210 Ω, and the actual power of the electric iron is: P = U2, actual r = (110 V) 21210 Ω = 10 W
The specification of an electric iron is "220 V & nbsp; & nbsp; & nbsp; 110 W". Please answer the following questions: (1) what is the normal working current of the electric iron? (2) What is the resistance of the electric iron? (3) How much heat does it produce when it is electrified for 10 minutes at rated voltage?
(1) (2) resistance of electric iron r = u2p = (220V) 2110w = 440 Ω. (3) generated heat q = w = Pt = 110W × 10 × 60s = 6.6 × 104j
The electric iron of 220 V and 100 W is connected to the 220 V power supply. It is required to (1) calculate the power consumed by the iron and (2) draw the current and voltage vector diagram
There's no problem with the title, right? The answer is in the title. What can I ask you?
(1) 100W electric soldering iron, rated voltage of 220 V, connected to 220 V power supply, consumption of electric power is 100 W
(2) Electric iron belongs to pure resistive load, so the current and voltage are in phase when connected to AC power supply
RELATED INFORMATIONS
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