The drift velocity of electrons in a conducti | vedclass

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(C) The drift velocity $v_d$ of electrons is very small (typically $10^{-3} \, m/s$).However,the electric field is established throughout the entire l

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The electric field is established in the wire very rapidly,and the current produced through every cross-section is almost instantaneous.

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(C) The drift velocity $v_d$ of electrons is very small (typically $10^{-3} \, m/s$).However,the electric field is established throughout the entire length of the wire at the speed of light $(c \approx 3 	imes 10^8 \, m/s)$ as soon as the switch is closed.This electric field exerts a force on all free electrons in the wire simultaneously,causing them to drift and establishing a current throughout the circuit almost instantaneously.Therefore,the bulb glows immediately because the electric field propagates rapidly,not because individual electrons travel from the switch to the bulb.

The drift velocity of electrons in a conducting wire is of the order of $1 \, mm/s$. However,when the switch is turned on,the bulb glows almost instantaneously. This is because:

Similar Questions

In the given figure,a battery of emf $E$ is connected across a conductor $PQ$ of length $L$ and different area of cross-sections having radii $r_{1}$ and $r_{2}$ $(r_{2} < r_{1})$. Choose the correct option as one moves from $P$ to $Q$:

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