How many amps does it take to light a 100 watt light bulb?

Answer 1

Watts = Amps * Volts

100 watts = x amps * 120 volts

100 watts / 120 volts = ~.83 amps
When lighted, a 100 watt 120 volt bulb takes 0.83 amps on a 120 volt supply (100 / 120 = .833)

However, an incandescent bulb may take ten times it's operating current for an instant as the filament heats up. That's why bulbs often burn out just as they are switched on - the high current and the sudden temperature change stress weak points in the filament.

Answer 2

A typical resistance for a cold light bulb is about 10 ohms. The initial current on a 120 v system is therefore 12 amps (120/10) but the resistance increases rapidly as the bulb's tungsten filament heats up

After about 13 milliseconds the bulb has reached its working resistance of 144 ohms and the current drawn is roughly 0.83 amps (for a 100 watt bulb at 120 v).

The true inrush current is the area under the curve obtained from an oscilloscope trace reading. However, if this reading is not available, then it is safe to assume that for incandescent lightbulbs the inrush current is around 10 times the normal current. However the inrush is over so quickly that the fuse is not in danger of blowing (edited to remove 'gibberish').

Answer 3

When lighted, a 100 watt 120 volt bulb takes 0.83 amps on a 120 volt supply (100 / 120 = .833)

However, an incandescent bulb may take ten times it's operating current for an instant as the filament heats up. That's why bulbs often burn out just as they are switched on - the high current and the sudden temperature change stress weak points in the filament.

Answer 4

A 100 watt light bulb typically requires approximately 0.83 amps to operate, assuming a standard voltage of 120 volts. This can be calculated by using the formula P (power in watts) = I (current in amps) x V (voltage in volts).

Answer 5

The formula you are looking for is I = W/E. Amps = Watts/Volts

Answer 6

The formula you are looking for is I = W/E, Amps = 100/230.