Top best answers to the question «How does an electric bulb lights up as soon as we turn the switch on»
When we close the circuit, the electric field is established instantly with the speed of electromagnetic wave which cause electron drift at every portion of the circuit. Due to which the current is set up in the entire circuit instantly… It is due to this reason, the electric bulb glows immediately when switch is on.
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Although the electrons are actually moving through the wire slowly, we say that the speed of electricity is near the speed of light (extremely fast). What we really mean is that the effects from the electricity occur "instantly." The light comes on the instant you flip a switch. You do not have to wait for electrons to flow from the switch to the light.
When you close the switch electrons flow into the wire where they bump into the electrons already in the wire and push them along. The voltage wave (analogous to the pressure wave) travels along the wire at somewhere between a tenth and a half of the speed of light depending on the type of wire, and reaches the light bulb in a few nanoseconds.
Due to it, the current is set up in the entire circuit instantly. The current so set up does not wait for the electrons to flow from one end of the conductor to other end. It is due to this reason, the electric bulb glows immediately when switched on.
This heats the bulb and it glows. So, we see that the electricity doesn’t come from the power source. It comes from the free electrons which are present in the filament. Now, another question arises. Whenever we switch off a bulb, why does it remain lit for some time. Let’s explore. It is quite a logical question. When the light bulb is lit ...
How is that an electric bulb lights up as soon as we turn the switch on? Physics Inside a solid,the atoms are packed together with very little spacing between them.When a steady current flows through a conductor, the electrons in it move with a certain average 'drift speed'.This drift speed is very small,about 1mmps.
This slow jumping however will push electrons through the light causing it to light up very quickly since the electrons in the light jump forward as soon as the switch makes a contact
Originally Answered: How is it then that an electric bulb lights up as soon as we turn the switch on? When electricity runs thru a light bulb, a metal filament inside the bulb offers resistance to the electricity, this causes the filament to heat up to incandescent temperatures becoming bright.
Once one of the wires is removed from the power source or a “break” is made in the flow, the circuit is now “open” and the lamp will no longer light. In practical application, circuits are “opened” by such devices as switches, fuses, and circuit breakers. Two general circuit classifications are series and parallel.
The operation of the closed circuit depends on the elements that compose it, for example, in the resistive circuit shown above, the light bulb lights up as soon as it is closed. Instead, if one of the resistors is replaced by a discharged capacitor, the circuit becomes RC and the capacitor will charge to the source voltage.