Internal resistance of a cell

[Hendrix0402]

Hello maam/sir. I would like to reach for help on my online assignment. Can someone please help me answer this questions? These are one of the 20 items given by my proffesor. These are the last 3 that I can't answer. Can anyone help me please? I THANK YOU SINCERELY AS A STRIVING STUDENT.

The electromotive force of a standard cell is measured with a potentiometer that gives a reading of 1.3562 V. When a 1.0 megaohm resistor is connected across the standard cell terminals, the potentiometer reading drops to 1.3560 V. What is the internal resistance of the standard cell?

If a resistor rated at 5 watts and 6 volts are connected across a battery with an open circuit voltage of 6 volts. What is the internal resistance of the battery if the resulting current is 0.8 A?

A 12 volts battery has a 50 ampere-hour capacity. The internal resistance is 0.1 ohm. A 5 ohm load is connected for 5 hours. How many ampere-hours are still left?

 

[JimB]

These are all simple Ohms Law problems.

Try sketching a simple circuit diagram showing the battery and its internal resistance, and the external load resistor.

Using this you can calculate the current through the circuit, and the voltage at various points through the circuit.

JimB

 

[Hendrix0402]

Sorry to ask. But can you help me do it for me? I don't have a internet connection and just using my neighbor's wifi. Our professor didn't gave us any notes. And I can't really understand it. I'm sorry.

 

[Nigel Goodwin]

Sorry to ask. But can you help me do it for me? I don't have a internet connection and just using my neighbor's wifi. Our professor didn't gave us any notes. And I can't really understand it. I'm sorry.

This isn't a site to do your homework for you, and you don't even need an internet connection, it's simple ohms law - a piece of paper and a pencil is all you need.

In case you don't know ohms law V = I x R.

 

[audioguru]

Can't you ask your professor to teach you?

 

[Pommie]

If a resistor rated at 5 watts and 6 volts

What a strange way to state a resistor value. I'd guess that means it's a 7.2Ω resistor?

Mike.

 

[crutschow]

Do you understand OHm's law?
If not, then you need to learn that simple relationship between current, volage, and resistance.
That is what is used to solve the problems.