The bulb marked "6V & nbsp; 3W" is connected in series with an 18 ohm resistor and connected to a 9V power supply. What is the actual power of the bulb?

According to P = u2r: R1 = u2p = 363 = 12 Ω, the total resistance of the two lamps in series is r = R1 + R2 = 30 Ω; according to Ohm's law I = ur = 9v30 Ω = 0.3A, the actual power of the bulb is p = i2r1 = (0.3A) 2 × 12 Ω = 1.08w; answer: the actual power of the bulb is 1.08w

Connect 2 ohm and 3 ohm resistors in series and connect them to a 10V power supply. The power consumed by 2 ohm resistor is
A:4W
B:6W
C:8W
D:10W

C
Current I = u / (R1 + R2) = 10 / 5 = 2A
Power P = I ^ 2 * R1 = 4 * 2 = 8W

After a small bulb is connected in series with a 50 Ω resistor and connected to a 10V power supply, it can light normally. At this time, the power of the small bulb is 5W, so the resistance of the small bulb when it lights normally is 5W____ Ω, the rated voltage is_ V,
(explain the reason)
Sorry, wrong number
When a small bulb is connected in series with a 5 Ω resistor and connected to a 10V power supply, it can emit light normally. At this time, the power of the small bulb is 5W, so the resistance of the small bulb when it emits light normally is 0 Ω, the rated voltage is_ V。

Because the series circuit R = R1 + R2
So r = R light + 5
And because I = P / R
So the small bulb current I = 5 / R lamp under root
Because the current of series circuit is equal and Ohm's law u = IR
So there is the equation (r Lamp + 5) times 5 / R lamp = 10 under the root sign
Solution r light = self solution
Rated voltage = R lamp P under root
Some symbols are not typed back and are replaced by words

The rated power of 1 lamp is 8W. It normally lights when connected in series with a 4.5 ohm resistor on a 15V power supply. The rated voltage and resistance of the lamp are calculated

Set the rated voltage as X
Because the lamp lights normally, the current I of the series circuit is 8 / x, so the voltage on the resistor is 4.5 * 8 / X
So we have X + 4.5 * 8 / x = 15
=>X ^ 2-15x + 36 = 0 = > x = 12V or x = 3V
According to P = u ^ 2 / R, the resistance is 18 ohm or 9 / 8 ohm
The rated voltage is 12V and the resistance is 18 ohm, or the rated voltage is 3V and the resistance is 9 / 8 ohm

The bulb marked "6V & nbsp; 3W" is connected in series with an 18 ohm resistor and connected to a 9V power supply. What is the actual power of the bulb?