Table of Contents
What is the resistance for a light bulb?
The typical cold resistance of a 100 W incandescent lamp is about 9.5 ohms. If that resistance stayed the same with 120 V applied, Ohm’s Law tells us that the bulb would draw about 12.5 amps and dissipate about 1,500 watts.
How do you calculate the resistance of a bulb?
Calculating resistance
- To find the resistance of a component, you need to measure:
- The resistance is the ratio of potential difference to current.
- For example, 3 A flows through a 240 V lamp.
- resistance = 240 ÷ 3 = 80 Ω
- If you plot a graph of current against potential difference for a wire, you get a straight line.
What is a 10 watt bulb equivalent to?
A 60-watt incandescent light bulb can be replaced with a 10-watt LED. E.
What is the resistance of a 12v 5w bulb?
To do this the resistor must be connected across the bulb and not in line with the + leg. I think that the resistors that are shown in the original link are for side light bulbs which are 5w, which at 12v give a resistance of approx 30 ohms.
How many ohms is a 60 watt light bulb?
240 ohms
The filament in a 60 watt bulb has a resistance of 240 ohms as compared to 145 ohms for a 100 watt bulb.
What is the approximate hot resistance of a 40W 120vac incandescent bulb?
So a 40W bulb at 120V would be 360 ohms, and you measure 26 ohms when cold.
What is the resistance of a bulb rated 100w 220v?
According to the question, the power rating of the bulb is 100 watts, and the rms value of the voltage across the bulb is 220 volts. So, substitute P=100 watts and Vrms=220 volts in the formula P=V2rmsR to determine the resistance of the bulb. Hence, the resistance of the bulb is 484 ohms.
What is 10W LED equivalent?
Lumen & Wattage Comparison
Lumens (Brightness) | LED Watts (Viribright) | Incandescent Watts |
---|---|---|
400 – 500 | 6 – 7W | 40W |
650 – 850 | 7 – 10W | 60W |
1000 – 1400 | 12 – 13W | 75W |
1450-1700+ | 14 – 20W | 100W |
How bright is a 10W?
As an easy example, we’ll work this out using a 10-Watt light bulb that emits 1000 lumens. One 10W light bulb might be much more efficient than another 10W light bulb; a particular 8W light bulb might not actually be as bright as a similar 6W light bulb.
Is the resistance of a 100 W bulb greater or less than the resistance of a 60 W bulb?
Hence, 100 W bulb filament is thicker than that of 60 Wbulb .
What is the resistance of a 60 watt light bulb?
A typical incandescent 60 watt bulb, for instance has a cold resistance of about 30 ohms, and a hot resistance of about 240 ohms. As the bulb gets hotter, the resistance increases. What happens to the power of an electric circuit if the resistance is decreased?
What is the cold resistance of a tungsten filament bulb?
The cold resistance of tungsten-filament lamps is about 1/15 the hot-filament resistance when the lamp is operating. For example, a 100-watt, 120-volt lamp has a resistance of 144 ohms when lit, but the cold resistance is much lower (about 9.5 ohms).” ( http://en.wikipedia.org/wiki/Incandescent_light_bulb )
How do you calculate the resistance of LED light bulbs?
LED bulbs are extremely non-linear. So in circuit of choice measure the voltage and the current. Resistance equals voltage divided by current. Volt is 230 , Power is 100 watts (bulb), Amps / Current is 0.434, Resistance is 529.953 Ohms. to obtain the resistance of a 100 watt bulb its’s 230 volts divided by amps / current 0.434 = 529.953 Ohms.
How do you know the power of a light bulb is constant?
A normal mathematical thinking can confirm that. If the voltage and current don’t change, then the power is constant. The electricity supplied from the wall is at 115V (more or less). If the resistance of the bulb is 1322 ohms, then the current is 87 milliamps. This give the power for the bulb as 10 Watts.