Question 391: Current Electricity

Question

In the given circuit all resistances are of value $R$ $ohm$ each. The equivalent resistance between $A$ and $B$ is :
![](https://app-content.cdn.examgoal.net/fly/@width/image/1l7u78plq/58a184c0-da3b-4c96-b550-168f37e4864d/f73f7be0-3016-11ed-ab58-4f43f7f8c851/file-1l7u78plr.png?format=png)

Accepted Answer

Let us assume potential at point M is X volts. Now you can see a plain wire is directly connected between point N and point M so point N will also have same potential as point M.
Similarly,  a plain wire is directly connected between point N and point O so point O will also have same potential as point N.
Also, a plain wire is directly connected between point O and point P so point P will also have same potential as point O.
Now you can see point P and point M both have same potential X, so no current will flow through that path so you can remove that resistor. Similarly, as point O and point M both have same potential X, so no current will flow through that path also so you can remove that resistor too.
So new circuit becomes
$ 	herefore $ R
AB
= R + R = 2R
![](['https://imagex.cdn.examgoal.net/1da9i2ynkd5wmi4x/2e25e0b0-dd37-4064-b847-2347b40068d5/256f5320-d0cc-11ea-b796-4745b429ed6f/file-1da9i2ynkd5wmi4y-860w.jpg', 'https://app-content.cdn.examgoal.net/fly/@width/image/1l7u79eue/f2a17ef4-2794-4743-86b7-2be3b0ab24b1/0abef060-3017-11ed-ab58-4f43f7f8c851/file-1l7u79euf.png?format=png'])

Answer

$2R$

Answer

$3R$

Answer

${{5R} \over 3}$

Answer

${{5R} \over 2}$

Current Electricity

In the given circuit all resistances are of value R ohm each. The equivalent resistance between A and B is :

Choose the correct answer: