Advertisements
Advertisements
Question
How does drift velocity of electrons in a metallic conductor vary with increase in temperature? Explain.
Advertisements
Solution
Drift velocity of electrons in a metallic conductor decreases with increase in temperature.
As we know,
As, we increase the temperature of the metallic conductor the collision between the electrons and ions increases, which results in the decrease in the relaxation time. so, from the equation (4)
vd ∝ r
Hence, the drift velocity decreased.
APPEARS IN
RELATED QUESTIONS
Write its (‘mobility’ of charge carriers) S.I. unit
Explain the term ‘drift velocity’ of electrons in conductor. Hence obtain the expression for the current through a conductor in terms of ‘drift velocity’.
A conductor of length ‘l’ is connected to a dc source of potential ‘V’. If the length of the conductor is tripled by gradually stretching it, keeping ‘V’ constant, how will (i) drift speed of electrons and (ii) resistance of the conductor be affected? Justify your answer.
Electrons are emitted by a hot filament and are accelerated by an electric field, as shown in the figure. The two stops at the left ensure that the electron beam has a uniform cross-section.

Obtain the expression for the current flowing through a conductor having number density of the electron n, area of cross-section A in terms of the drift velocity vd .
Metals are good conductor of heat than insulator because
Consider two conducting wires A and B of the same diameter but made of different materials joined in series across a battery. The number density of electrons in A is 1.5 times that in B. Find the ratio of the drift velocity of electrons in wire A to that in wire B.
What does conductivity, denoted by \[\sigma\], measure?
Why do free electrons in a metal move randomly when no electric field is present?
