Class 12th Physics Physics Current Electricity Overview

A uniform wire of resistance $R$ is stretched uniformly to $n$ times. It is then cut to form five wires of equal length. These wires are arranged as shown in figure. the effective resistance between $A$ and $C$ is

Option 1 - <p><span class="mathml" contenteditable="false"> <math> <mfrac> <mrow> <mrow> <msup> <mrow> <mrow> <mi>n</mi> </mrow> </mrow> <mrow> <mrow> <mn>2</mn> </mrow> </mrow> </msup> <mi>R</mi> </mrow> </mrow> <mrow> <mrow> <mn>3</mn> </mrow> </mrow> </mfrac> </math> </span></p>

Option 2 - <p><span class="mathml" contenteditable="false"> <math> <mfrac> <mrow> <mrow> <msup> <mrow> <mrow> <mi>n</mi> </mrow> </mrow> <mrow> <mrow> <mn>2</mn> </mrow> </mrow> </msup> <mi>R</mi> </mrow> </mrow> <mrow> <mrow> <mn>5</mn> </mrow> </mrow> </mfrac> </math> </span></p>

Option 3 - <p><span class="mathml" contenteditable="false"> <math> <mfrac> <mrow> <mrow> <mi>n</mi> <mi>R</mi> </mrow> </mrow> <mrow> <mrow> <mn>5</mn> </mrow> </mrow> </mfrac> </math> </span></p>

Option 4 - <p><span class="mathml" contenteditable="false"> <math> <mfrac> <mrow> <mrow> <mi>n</mi> <mi>R</mi> </mrow> </mrow> <mrow> <mrow> <mn>3</mn> </mrow> </mrow> </mfrac> </math> </span></p>

11 Views|Posted 4 months ago

Asked by Shiksha User

1 Answer

Sort by:

A

Answered by

Alok Kumar Singh | Contributor-Level 10

4 months ago

Correct Option - 2

Detailed Solution:

When wire is stretched uniformly

$R \propto R$

$\frac{R}{R^{'}} = {(\frac{l}{n l})}^{2} = \frac{1}{n^{2}}$

$R^{'} = n^{2} R$

When this elongated wire is cut into 5 parts, resistance of each part

Effective resistance between A and C $= \frac{n^{2} R}{5}$

Upvote

Thumbs Down Icon

Similar Questions for you

A potentiometer wire of length 100 cm has resistance of 20 ohm. It is connected in series with an external resistance and a cell of emf 2 volt and of negligible internal resistance. A source of emf 20 mV is balance against a length of 40 cm of the potentiometer wire. What is the value of external resistance?

Alok Kumar Singh

A battery of emf, 20 V is connected to resistances as shown in figure. The potential at the point C will be

Alok Kumar Singh

Ohm’s law is valid if

Alok Kumar Singh

Ohm's law is valid if I depends on V' linearly.

An object 1 cm tall is placed at 4 cm infront of a mirror, In order to produce an upright image of 3 cm height one needs a :-

Alok Kumar Singh

In a step up transformer, if ratio of turns of primary to secondary is 1 : 10 and primary voltage is 230 V. If the load current is 2A, then the current in primary is :-

Alok Kumar Singh

Taking an Exam? Selecting a College?

Get authentic answers from experts, students and alumni that you won't find anywhere else.

On Shiksha, get access to

66K

Colleges

|

1.2K

Exams

|

6.9L

Reviews

|

1.8M

Answers

Learn more about...

Physics Current Electricity 2025

Physics Current Electricity 2025

View Exam Details

Most viewed information

Share Your College Life Experience

Didn't find the answer you were looking for?

Search from Shiksha's 1 lakh+ Topics

or

Ask Current Students, Alumni & our Experts

Quick Actions

Community GuidelinesUser Points System

QuestionsDiscussionsTags

Have a question related to your career & education?

or

See what others like you are asking & answering