JEE Main 2018PhysicsCurrent ElectricityElectric Current Current Density And Drift VelocityeasyMCQ

JEE Main 2018 — Current Electricity Question with Solution

From: JEE Main 2018 (Online) 15th April Evening Slot

Question

A copper rod of cross-sectional area A carries a uniform current I through it. At temperature T, if the volume charge density of the rod is , how long will the changes take to travel a distance d ?

Choose an option

Show full solutionCorrect option: C
Correct answer
C

Step-by-step explanation

Given : Volume charge density of rod = .

We know that current ; where n is number of electrons, e is electronic charge, A is area, vd is drift velocity

JEE Main 2018 (Online) 15th April Evening Slot Physics - Current Electricity Question 297 English Explanation

Since volume charge density is = ne. Therefore,

Now, time =

time

Thus, time required to travel distance

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About this question

This is a previous-year question from JEE Main 2018, covering the Current Electricity chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.