Can you measure the resistance of a light bulb?

Although you may not measure the resistance of the bulb directly, you can measure the voltage drop across the bulb and the current through the bulb, and this measure the resistance indirectly, calulating resistance by dividing voltage by current.

Why is the measured resistance and the calculated resistance of the light bulb so different?

For a non-ohmic material, the calculated resistance at low current is different from the resistance at high current. An increase in current means the bulb gets hot—hot enough to glow. As the temperature increases, however, the resistance also increases.

What happens if you measure resistance with power on?

A resistance measurement must be performed with the power off. The way that a meter measures resistance is that it actually puts a small current across the probes and measures the resulting voltage. The resistance reading is meaningless if there is already voltage on the thing you’re measuring.

What happens to the resistance of your light bulb if you increase the voltage of your battery?

The current which flows through the circuit depends upon the number of electrons flowing through the circuit per second. When using batteries, increasing the voltage also increases the current in the circuit. In a parallel circuit, as electrical devices are added the resistance decreases.

How do you know when a light bulb is bad?

how to tell if a light bulb is blown:

1. it doesnt work in the light socket.
2. it rattles when you shake it (because the filament is broken)
3. you can see that the filament is broken inside the bulb.
4. also – blackening of the globe is a bit of a giveaway too…. 🙂

Why does resistance change in a light bulb?

The resistance of a filament lamp increases as the potential difference increases because the filament becomes hot. The movement of electrons (which is what causes the current) makes the atoms inside the filament vibrate faster and this makes the filament heat up.

Why is resistance useful in light bulbs?

Resistance causes some of the electrical energy to turn into heat so some electrical energy is lost along the way. However, it is resistance that allows us to use electricity for heat and light. The heat that is generated from electric heaters or the light that we get from light bulbs is due to resistance.

Why can’t you measure resistance on an energized circuit?

A meter has a known voltage, and a measured current so the resistance is calculated, or a known current and a measured voltage, so once again, the resistance is calculated. But when your circuit is powered, the voltage and/or current are no longer a known value, so neither is the resistance.

Why do we measure resistance?

Why measure resistance? To determine the condition of a circuit or component. The higher the resistance, the lower the current flow, and vice versa.

What would happen to a light bulb if the voltage increased but the resistance stayed the same?

But also if voltage is constant and resistance decreases, then current increases so that means that the bulb glows brighter too because more coulombs are flowing through it per second.