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amaresh92
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Homework Statement
greetings
why a bulb glow dimmer in beginning and then brighter when it is connected to a inductor?
thecritic said:Because, inductor won't let current to switch instantaneously, i.e., it will make current rise slowly to its final value.
If you work out the math by assuming that the rate at which inductor let's current to rise is proportional to voltage across it, i.e. dI/dt = (1/L) V, then applying KVL, you will come to a differential equation.
Solving the differential equation, you will get expression for current, i.e. current as a function of time, I(t), which will give you all the information you need.
The initial dimness of a bulb's glow is due to the flow of electricity causing the filament to heat up. As the filament heats up, it increases the bulb's resistance, which results in a lower flow of electricity and a dimmer glow.
As the filament continues to heat up, its resistance decreases, allowing more electricity to flow through and increasing the bulb's brightness. This process is known as thermal equilibrium and is why the bulb gradually gets brighter over time.
The filament of a bulb has a high melting point, so it takes time for it to reach its maximum temperature and brightness. Additionally, the filament's resistance increases as it heats up, slowing down the flow of electricity and further delaying the bulb's maximum brightness.
Yes, using a preheat circuit can prevent the initial dimness of a bulb. This circuit allows a small amount of current to flow through the filament before the bulb is fully turned on, preheating the filament and reducing its resistance, resulting in a brighter initial glow.
Yes, the dimness and brightness of a bulb can be controlled by adjusting the voltage and current flowing through it. Using a dimmer switch or varying the input voltage can change the amount of electricity flowing through the filament, thus controlling the bulb's brightness.