Basic Resistors problem

I am very confused over few of the equivalent resistance finding questions. I am unable to figure out how to take resistors; in parallel or in series especially in questions which have awkward shapes. I want to have my basics clear, so I want some help! This is one of the problems I was unable to solve:

#ElectricityAndMagnetism

Easy Math Editor

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Comments

Did this question seriously appeared in your school paper?.

I Think its a bit complicated as it involves Unbalanced wheatstone bridge which can be solved by using Kirchoff's law only

or check that if by mistake you have Interchanged the position of one two ohm and 10 ohm resistance pair . then it will be a balanced one and can be solved easily.

Prakhar Bindal - 4 years, 9 months ago

Yep...it really did but teachers have given everyone +2 for this one because it was of higher standard than what we have been taught..

Yatin Khanna - 4 years, 9 months ago

For better understanding mark the points with different potentials and then re draw the figure.

Note that whenever a resistor or a battery comes in between two points there potentials will be different (if they aren't shorted of course)

In above case start from A The point following A Will also be A as they will be of same potential (no potential drop across a wire) . Next you have two paths you can move till 2 ohm resistor . the point just preceding 2 ohm will be A and the point following 2 ohm will be C . They wont have the same potential as there might be some voltage drop across the resistance.

Similarly Mark all other points.

You will see that you will have only 4 points of different Potential A , B And two others.

Then redraw the figure by taking 4 points on the page and connect the resistors between there corresponding points.

Try it out it will be easy!

Prakhar Bindal - 4 years, 9 months ago

https://goo.gl/photos/k7UrqRgwZRQtwJNv6 This should solve your problem. (hoping that you know wheatstone bridge)

Ankith A Das - 4 years, 9 months ago

Unfortunately your diagram is incorrect! . The 5 ohm resistor isn't directly connected between A And B . It will be between upper and lower points.

And that would result into an Unbalanced wheatstone bridge!

Prakhar Bindal - 4 years, 9 months ago

Oh shit you are right Made a mistake while copying the figure from the second step Thanks bro

Ankith A Das - 4 years, 9 months ago

Unfortunately, no! But I heard about it...something like a resistor being short circuited or no current passing through it..

Yatin Khanna - 4 years, 9 months ago

Then I would recommend you to learn that first. You should learn Kirchoff's laws too before you start attempting such problems.

Ankith A Das - 4 years, 9 months ago

The fact is that this question appeared in my school's round test paper; and all what we have learnt till now is series amd parallel.

Yatin Khanna - 4 years, 9 months ago

Ohh. That's weird. It's okay, you can learn it now.It is not that hard.

Ankith A Das - 4 years, 9 months ago

Math	Appears as
Remember to wrap math in `\(` ... `\)` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$