Home Physics Current Electricity General An electrical cable of copper has just one w…
Physics Current Electricity General MCQ (Single Correct)

An electrical cable of copper has just one wire of radius 9 mm. Its resistance of 5 Ω Ω . This single copper wire of cable is replaced by 6 different well insulated copper wires, each of radius 3 mm. The total resistance of cable will now be equal to-

A
7.5 Ω Ω
B
45 Ω Ω
C
90 Ω Ω
D
270 Ω Ω

Share this question

For Instagram sharing, use “Apps” on mobile or copy the link.

Text Solution

Verified by Experts
The correct answer is:
A

According to given problem
Resistance of a wire
where is the length of a wire is the radius of a wire
is the specific resistance of a wire

with
Now as the new radius of a single wire is
i.e., r/3 its resistance.

And when 6 wires each of resistance are connected in parallel to form the new cable

Prepare Smarter with CGP Edu

Get practice questions, solutions, and test series in one place.

Write a Review

Share your experience with this question and solution.

Commentary

Send your comment, doubt, correction, or feedback to admin.

Student Reviews

What students say about this solution

No reviews yet. Be the first to write a review.

Similar Questions

Explore conceptually related problems

CG
CGP Question Assistant Question Bank + AI Help
Hi! Type your question or upload one screenshot. First I will search related questions from CGP Edu Question Bank. If none match, type YES and I will solve it with AI.
Upload only one screenshot at a time. Flow: Question Bank first → If not matched, type YES for AI solution.