# Physics

posted by .

I'm doing a report on my experiment right now where you had to test out the voltage and current of 2 resisters and a light globe with an ammeter and voltmeter. We had to graph the results, and the reisistors had a linear relationship between voltage and current, but the light globe is either exponential or power. Can anyone explain why this is? Is it a systematic error?

• Physics -

Believe your data. The tungsten filament of a light bulb has a resistance that increases with temperature, and as you raise the voltage, the filament becomes much hotter.

Many materials have a resistance that varies with temperture, but the effect is more noticeable with light bulb filaments because they are designed to get very hot, in order to emit light.

• Physics -

So basically, the light bulb's resistance varies?

## Similar Questions

1. ### Physics EM

An ammeter is connected in series to a battery of voltage V_b and a resistor of unknown resistance R_u The ammeter reads a current I_0. Next, a resistor of unknown resistance R_r is connected in series to the ammeter, and the ammeter's …
2. ### College Physics

When switch S in the figure is open, the voltmeter V of the battery reads 3.13V . When the switch is closed, the voltmeter reading drops to 2.90V , and the ammeter A reads 1.70A. Assume that the two meters are ideal, so they do not …
3. ### Physics

Ammeter 1 reads 0.20 A. a. What should ammeter 3 indicate?
4. ### Physics

Ammeter 1 reads 0.20 A. a. What should ammeter 3 indicate?
5. ### engineering science

The power in a resistor RLOAD of 10 Ω when connected to a 100 volt supply is measured using a voltmeter and ammeter. There are two possible ways of connecting the meters as shown in FIGURE 2. The resistances RA and RV represent …
6. ### Physics

What is the maximum equipment needed to determine the power dissipated in a resistor of unknown value?
7. ### physics

A) If voltmeter measures 2V across a 50 ohm resistor what current goes through the resistor?
8. ### Physics

A ammeter is to be constructed using a galvanometer that has a 2.00 mA full-scale deflection and internal resistance of 50.0 ohms. It must be good enough to detect 40 mA, which is the max current. How would one do this?
9. ### physics

When the lights of an automobile are switched on, an ammeter in series with them reads 9.70 A and a voltmeter connected across them reads 12.20 V. When the electric starting motor is also turned on, the ammeter reading drops to 7.30 …
10. ### physics

1)a galvanometer has a resistance of 40 ohm and is of 3 mA full-scale deflection.how would you modify it to act as a 0-5 A ammeter?

More Similar Questions