# 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:

Note by Yatin Khanna
3 years, 2 months ago

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

• Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
• Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
• Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
• Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold
- bulleted- list
• bulleted
• list
1. numbered2. list
1. numbered
2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears 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} $\boxed{123}$

Sort by:

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!

- 3 years, 2 months ago

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.

- 3 years, 2 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..

- 3 years, 2 months ago

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

- 3 years, 2 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!

- 3 years, 2 months ago

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

- 3 years, 2 months ago

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

- 3 years, 2 months ago

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

- 3 years, 2 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.

- 3 years, 2 months ago

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

- 3 years, 2 months ago