Calculating Internal Resistor in a Series Battery Circuit

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Homework Statement



Helping someone regarding this Qns:

A Battery is formed by four 1.5 V identical cell in series. When a external resistor of 31 Ohm is connected across he battery, the current is 280 mA. Find the internal resistor of each cell.

Can someone help to solve pls?

Thank you loads (:

Homework Equations



V = E - Ir ?

The Attempt at a Solution

 
Last edited:
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helper- said:
1. V = E - Ir ?



No, try R = E/i
 
R = e / i = 6V / 0.290A = 21.43 Ohms

**is this is less than the load resistance of 31 Ohms?

The answer given is 0.19 Ohms; but unable to solve. Any idea?
 
helper- said:
R = e / i = 6V / 0.290A = 21.43 Ohms

**is this is less than the load resistance of 31 Ohms?

The answer given is 0.19 Ohms; but unable to solve. Any idea?

It's 0.290 A, not 0.280.

What limits the current thru the 31 ohm resistor?
 
something wrong here ! 6V emf, current of 0.28A means total R = 6/0.28 =21.4 ohms
Does not fit with external resistance of 31 ohms connected.
Check the question
 
truesearch said:
something wrong here ! 6V emf, current of 0.28A means total R = 6/0.28 =21.4 ohms
Does not fit with external resistance of 31 ohms connected.
Check the question

That's right, it's impossible.
 
*opps type on the 0.28.

Thanks all! Guess have to check with the lecturer, seems the qns is wierdddd. (:
 

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