Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

A cylindrical resistor has a length Land radius r. This piece of material is then drawn so that it is a cylinder with a new length of 2L. What happens to the area of this material because of this process?


see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

a

the resistance is quartered.

b

the resistance is quadrupled.

c

the resistance is unchanged.

d

the resistance is doubled.  

answer is D.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

The area of this material because of this process, the resistance is doubled.
The resistance of a wire is expressed as
R=ρlA
where R- Resistance of the conductor, 
ρ(rho)- Resistivity (constant)
l-Length of the conductor
A- Area of a cross-section of the conductor.
So the length is directly proportional to the resistance (lR), and the area of the cross-section is inversely proportional to the resistance A1R
So, when the length is doubled, i.e., 2L and so the resistance will be  2R
Thus, for the resistance to remain the same as R, the area of the cross-section should also be doubled as 2A.
 
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring