A bulb marked with "pz220-100" works normally for 100 hours. How many kilowatts does it use? How many hours can the bulb marked with "pz220-40" work normally with 1 kwh of electricity?

(1) It is known that P = 100W = 0.1kw, w = Pt = 0.1kw × 100h = 10kW · h. answer: the lamp works normally for 100 hours, using 10 degree electricity. (2) p1 = 40W = 0.04kw, T1 = w1p1 = 1kW · h0.04kw = 25h. Answer: the lamp works normally for 25 hours

A light bulb is marked with pz220 100. How many hours can a light bulb work per kilowatt hour

One degree of electricity is 1000VA. H, and 1va = 1W, so one degree of electricity can provide one kilowatt of electrical appliances to work for one hour, or vice versa, it can provide one watt of electrical appliances to work for 1000 hours, then it can provide 100 watt of lamps to work for 10 hours

There is a bulb marked "220V 25W" with a resistance of 220 Ω (at this time, the bulb is not powered on)
Please calculate the actual electric power of the light bulb at the moment when it is just powered on, and explain why the light bulb is always easy to burn out at the moment when the switch is closed

P=U^/R=220^2/220=220W
At this time, the bulb is in the cold state, the resistance is very small, the power is very large, the current is also very large, so it is easy to burn out!

A bulb marked "220 V 25 W", what is the bulb resistance?

P=UI
25W=220V*I
I=5/44A
Resistance R = u / I = 220 / (5 / 44) a = 1936 Ω
Or: r = u ^ 2 / P = 220 ^ 2 / 25 = 1936 Ω

A bulb marked with "pz220-100" works normally for 100 hours. How many kilowatts does it use? How many hours can the bulb marked with "pz220-40" work normally with 1 kwh of electricity?