Why a bulb glow dimmer in beginning and then brighter

AI Thread Summary
A bulb connected to an inductor initially glows dimly because the inductor resists instantaneous changes in current, causing the current to rise gradually. The relationship between the rate of current change and voltage across the inductor can be expressed mathematically as dI/dt = (1/L) V, leading to a differential equation. Solving this equation provides a function for current over time, I(t), which illustrates the gradual increase in brightness. The maximum current or voltage achieved will match the steady-state values observed if the inductor were removed and replaced with a wire. This behavior highlights the inductor's role in controlling current flow in electrical circuits.
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greetings
why a bulb glow dimmer in beginning and then brighter when it is connected to a inductor?
 
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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.
 


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.

what will be the maximum value of votage or current?
 


The maximum value which is the final steady state value will be equivalent to what will be obtained if you remove the inductor and join with wire.
 
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