A bulb is connected in series with resistance R. the known bulb specification is "220V 1000W", the battery voltage is 220V, and the resistance of resistance R is 6.6ohm. Calculate the actual power of the bulb

A bulb is connected in series with resistance R. the known bulb specification is "220V 1000W", the battery voltage is 220V, and the resistance of resistance R is 6.6ohm. Calculate the actual power of the bulb

R lamp = u & sup2 / P = (220 V) & sup2 / 1000 W = 48.4 Ω
R total = R Lamp + R resistance = 55 Ω
I = u / R total = 220 V / 55 Ω = 4A
P real = I & sup2; R lamp = 16A × 48.4 Ω = 774.4w

The resistance of an arc lamp is 5 ohm, and the current of normal lighting is 2A. If you want to connect it to a 220 V power supply, you can still make it work
For normal lighting, a resistor must be connected

Answer: a 105 ohm resistor in series
Analysis:
The voltage of this lamp is:
U lamp = IR lamp = 2 * 5 = 10V
Therefore, the voltage of series resistance is:
U '= 220-10 = 210v, the current is the same as the lamp, 2A
Resistance: r = u '/ I = 210 / 2 = 105 Ω