i am a first year electroincs student.. i am haveing a bit of trouble with series/parellel circuits...the problem thet i am haveing is finding out witch resistors are in series and witch ones are in parellel..is their a easy way to figure this out??? i think i am just looking to much into the problems, makeing them much harder than they really are.. thank you very much for all the help......

 

If two or more resistors have their one side terminals connected together and their other side terminals also connected together then they are in parallel.

Resistors in series have just one common terminal

 

i think i understand this with just resistors, but when you put it in a problem is where i get lost...

 

Post an example to guide you

 

Imagine it like, if the electricity only has one way to go, it is wired in series. In parallel, the current can choose multiple paths.

 

how do i get a pic to post ???

 

You can photograph the display of your PC with the print screen button on the keyboard. You can find a circuit on the internet and post its link too.

 

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these are just a few of the problems i have to work on.. i just need some way to understand how to figure it out... i know the formulas,i just need a to get it in my head...thanks

 

Ok lets take figure 6.20

R7, R8 and R9 are in series so we add them to get say Ra=R7+R8+R9

Then Ra is in parallel with R5, we make the calculation to get Rb=Ra//R5

Then R4, Rb and R6 are in series, we calculate to get Rc=R4+Rb+R6

Then Rc is in parallel with R2, calculate them to get Rd=Rc//R2

Finally, R1, Rd and R3 are in series, calculate to get Requivalent=R1+Rd+R3

Ra, Rb, Rc and Rd are just the values of some of the combinations, dont get confused. Also, this // means in parallel.

 

Fig. 6-8:
R2 and R3 are in series. R2+R3=Ra.
Then Ra and R4 are in parallel.
Rb=(Ra x R4) / (Ra + R4)

Then R1, Rb, and R5 are in series. Add them up.

 

thank you very much..i am going to try to solve some of these and see if i can get this stuck into my thick head..thanks again

 

Try a few - then take a break Letting your subconcious chew on things for a bit can help sort things out.

A couple of quick cross-checks:
When you're calculating the total resistance of two or more resistors in parallel, your result will always be less than the smallest resistor's value.
When you're calculating the total resistance of two or more resistors in series, your result will always be greater than the largest resistor's value.