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Why does the resistance of a light bulb change as it heats up?
This is because the filament gets hot, which causes the resistance to increase. At high temperatures, the atoms in the filament vibrate more. The electrons in the current now collide more with the atoms. As the potential difference increases, the current no longer increases as much.
Why is resistance less when bulb is not glowing?
Incandescent light bulbs have a small filament which when heated begins to glow and emit light. The reason the filament heats up is because it has a high resistance, which means that as electrons move through the filament, they lose a lot of energy, and so its resistance becomes low.
Does higher resistance mean more light?
If the bulb has a resistance less than that, then it will get brighter if you increase its resistance. If the bulb has higher resistance than optimum, then you get more power by reducing the resistance.
What happens to the resistance of a lamp as the current increases?
As the current through the lamp increases, the filament gets hotter and has a higher resistance. The resistance of a filament lamp increase as the current through the filament increases and hence as the temperature increases.
Which factor does not affect the resistance of a material?
The resistance of a conductor does not depend on Pressure. Conductors show less resistance and Insulators show very high resistance. So it depends on the material. It is inversely proportional to the cross-sectional area of the wire.
How many bulbs of resistance 6 ohm should be joined in parallel to draw a current of 2 ampere from a battery of three balls?
Hence 4 bulbs are connected in parallel.
How does resistance affect the brightness of a light bulb?
An incandescent bulb’s brightness depends on a whole lot on resistance. The higher the resistance to current in the wiring, circuitry, and bulb, the lower will be the current, lower the power, and lower the brightness. Conversely, lower resistance means more brightness.
Does current increase with resistance in a filament lamp?
For a filament bulb, voltage and current are not directly proportional as the graph is not a straight line through the origin. Doubling the voltage does not double the current. It is clear from the resistance column in the results table that, as current increases the resistance of the lamp increases.
When resistance increases what happens to bulb?
As bulbs are added the resistance in the circuit decreases since each circuit is another pathway for electrons to move from one end of the circuit to the other.
What does brightness of a lamp depend on?
The brightness of the lamp (power) depends on two factors: The voltage and the current which flow through it. In Figure(A) as the variable reaistance increases its reaistance, the current which flow through the lamp will decrease and therefore its brightness decreases.