There is a bulb marked with "220V 40W". In order to connect the lamp to the 382v circuit for normal use, what is the resistance in series? I know the answer, but how?

The voltage at both ends of the series resistor is 382-220 = 162 v
Series resistance current 40 / 220 = 2 / 11 A
R = u / I = 162 * 11 / 2 = 891 ohm

19. (9 points) the rice cooker of a certain brand is marked with "220V 1100W", which is connected to the home circuit
2) What is the resistance of the appliance when it works? (3) if it works for 30 minutes, what is the power consumption?

1) I=P/U=1100/220=5A
2) R = u ^ 2 / P = 220 * 220 / 1100 = 44 ohm
3) Electric energy = 1100 * 0.5/1000 = 0.55 degree

In physics, there is a 220V 100W B electric appliance and a 110V 25W a electric appliance
If they are put into the circuit in series or in parallel, will the power consumed by a and B be equal? Why?

Power P = u & # / R
It is only related to voltage and resistance
The resistance of a and B is 484 ohm
And put them under the same voltage (parallel voltage must be equal, because the resistance is equal, when they are in series, the partial voltage is equal), so the power consumption is equal

At present, there are two bulbs A and B, which are marked with the words "220 V & nbsp; 100 W" and "220 V & nbsp; 40 W" respectively on the nameplates
A. When the two lamps light up normally, the power of a is higher. B. when the two lamps light up normally, the two lamps are on the same way. C. when the two lamps light up normally, the resistance of a lamp is higher than that of B lamp. D. connect them in series into a 220 V circuit, and both lamps can light up normally

A. The power of the bulb is equal to the rated power when it normally emits light, so a is correct when the two bulbs normally emit light. B. the brightness of the bulb depends on the actual power. When the two bulbs normally emit light, the actual power of bulb a is higher and the bulb is brighter, so B is incorrect. C. according to P = u2r, the voltage when the two bulbs normally emit light is 220V, and the electric power of bulb a is higher C is not correct because of high efficiency and low resistance; D. when two bulbs are connected in series into the circuit of 220 V, the voltage they share is less than 220 V, so it is impossible to light normally, so D is not correct, so a is selected

There is a bulb marked with "220V 40W". In order to connect the lamp to the 382v circuit for normal use, what is the resistance in series? I know the answer, but how?