# Equivalent resistance if the values of the two resistances

1. May 2, 2009

### XodoX

Two resistors are in series. Find the equivalent resistance if the values of the two
resistances are as follows.
a) 10 [Ω] and 20 [Ω].
b) 100 [Ω] and 1 [MΩ] (M stands for “Mega” or million).
c) 3.0 [kΩ] and 6.7 [kΩ] (k stands for “kilo” or thousand).
d) 400 [Ω] and 1 [Ω].

Repeat the above problem, assuming that the resistors are in parallel.

Can anybody hel me with this, please? I have no idea how to start/do this.

Thank you!

2. May 3, 2009

### Defennder

Re: resistors

To start you off, what do you know about how to find equivalent resistance of resistors in series and parallel?

3. May 3, 2009

### XodoX

Re: resistors

parallel has the same voltage and the current in series stays the same?

4. May 3, 2009

### M11

Re: resistors

Series resistors:

Requivalent=R1+R2+R3+.......+Rn

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Parallel resistors:

( 1/ Requivalent) = ( 1 / R1) + ( 1/ R2) +........+ ( 1/ Rn)

OR you can use the following equation if you have two parallel resistors:

Requivalent=$$\frac{R1 \times R2}{R1 + R2}$$

Last edited: May 3, 2009
5. May 5, 2009

### XodoX

Re: resistors

So I just add them? a) would be 30 then.
Thank you, that works:)

Last edited: May 5, 2009