current-electricity Question 2
Question: Q. 2. Which of the following characteristics of electrons determines the current in a conductor?
(a) Drift velocity alone.
(b) Thermal velocity alone.
(c) Both drift velocity and thermal velocity.
(d) Neither drift nor thermal velocity.
[NCERT Exemplar]
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Solution:
Ans. Correct option : (a)
Explanation : As we know that,
$$ I=\text { Anev }_{d} $$
So current,
$$ I \propto v_{d} $$
And, current (I) also depends on $n$, the number of free electrons which increase on increasing temperature which make more collisions between electrons increase resistance or decrease current.