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प्रश्न
Which of the following characteristics of electrons determines the current in a conductor?
पर्याय
Drift velocity alone
Thermal velocity alone
Both drift velocity and thermal velocity
Neither drift nor thermal velocity
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उत्तर
Drift velocity alone
Explanation:
Drift velocity is the average uniform velocity acquired by free electrons inside a metal by the application of an electric field, which is responsible for the current through it
The direction of drift velocity for electrons in a metal is opposite to that of applied electric field (i.e. current density `vec J`).
Vd ∞ E, i.e., the greater the electric field, the larger will be the drift velocity.
The relationship between current and drift speed is given by I = ne Avd
Here, l is the current, and vd is the drift velocity.
So, I ∞ vd
Thus, only drift velocity determines the current in a conductor.
Remember the direction of drift velocity and current is opposite, so we are taking the magnitude of drift velocity or drift speed of free electrons.
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