I need to solve this, but I need help...

'A battery having an emf of 105V and an internal resistance of 1 Ohm is connected in parallel with a d.c generator of emf 110V and internal resistance of 0.5 Ohm to supply a load having a resistance of 8 Ohms. Calculate: a) the currents in the battery, the generator and the load; b) the potential difference across the load.'

For question number a), is it right if I use 'V=Emf-Ir' please?

 

A good place to start is to draw a diagram with the 2 voltage sources and the 3 resistances.

 

A good place to start is to draw a diagram with the 2 voltage sources and the 3 resistances.

^ what he said.

 

I did draw it. Can you please tell me if V = Emf - Ir is the right equation to use for question number a)? Thank you.

 

If both positive terminals of the voltage sources are connected together, than that equation only tells you the voltage across the battery, not the voltage across the load.

 

Ok so it is wrong, thank you.

 

Hello,

As asked, post your schematic here, so we can have a look you made a correct one.
You can do this using the "Upload a File" button below the reply box.

Bertus

 

Part a asks you to find 3 things. To find 3 things, you need 3 equations.

 

Hi CG,
Is this your diagram.?

EMF is the open circuit voltage, so the V will be EMF - Iamp

But more maths are required to solve the problem.
E

 

Sounds like a job for Kirchoff's laws.

 

Sounds like a job for Kirchoff's laws.

yep

 

Oh, ok so I have to use Kirchoff's law. Thank you all. Also, thank you ericgibbs, for your diagram as I had drawn it in a different way, and did not realise what equation to use.

 

Oh, ok so I have to use Kirchoff's law. Thank you all. Also, thank you ericgibbs, for your diagram as I had drawn it in a different way, and did not realise what equation to use.

How do you know that their's is right?

 

How do you know that their's is right?

Who is theirs.???
Mine or the OP's.

My drawing was created from the very clear description posted by the OP.

 

Who is theirs.???
Mine or the OP's.

OP did not post any drawing or schematic.

 

Hi CG,
Look thru this link for guidance.
http://www.allaboutcircuits.com/vol_1/chpt_10/1.html
E

 

Thank you ericgibbs.

 

In the Top menu bar of this page , is an option named Text books, click and find the topic that you need help with.
E

 

I found it easier to use the Norton equivalent of the two sources and then find the equivalent resistance of the internals and the load.

 

Thank you.