There is a light bulb marked with 220 V, 100 W (1) The bulb is normally emitting. What is the current passing through the bulb? What is the resistance of the bulb? (2) How much power is consumed when the bulb works normally for 10 minutes?

There is a light bulb marked with 220 V, 100 W (1) The bulb is normally emitting. What is the current passing through the bulb? What is the resistance of the bulb? (2) How much power is consumed when the bulb works normally for 10 minutes?

（1）
I=P/U=100/220=5/11A
R=U^2/P=220^2/100=484Ω
（2）
W=Pt=100*10*60=6*10^4J

A light bulb marked "220 V, 100 W" means "100 W"?

Under the rated voltage of 220 V, the rated power of the bulb is 100 W

Three bulbs in parallel, L1 "220 V, 100 W", L2 "220 V, 40 W", L3 "220 V, 25 W"
Find the voltage ratio of three bulbs
2 current intensity ratio
3 ratio of actual power consumption

1. The parallel voltage is equal, U1: U2: U3 = 1:1:1
2. According to I = P / u, I1: I2: I3 = P1: P2: P3 = 100:40:25 = 20:8:5
3.P1:P2:P3=100:40:25=20:8:5

The load gains the maximum power and the circuit efficiency is less
A100%B50%C25%D75%

B50%