Register to reply 
D.C circuits PLEASE help...are my answers correct? 
Share this thread: 
#1
Feb2707, 03:47 PM

P: 27

1. The problem statement, all variables and given/known data
To find the emf and internal resistance of an unmarked battery you are given two resistor of value 5.0(ohms) and an ammeter. When the resistors are connected in parallel the current drawn from the battery is 2.0A. What are the e.m.f and internal resistance of the battery? Am i going right? 2. Relevant equations E = IR = Ir 3. The attempt at a solution Series R = 5(ohms) + 5(ohms) = 10(ohms) Parellel 1/R = 1/5 + 1/5 = 2/5 R = 2.5(ohms) E = 0.75*10 + o.75*r E = 7.5 + 0.75r  (1) E = 2*2.5 + 2r E = 5 + 2r  (2) 7.5 + 0.75r = 5 +2r 2.5 = 1.25r 2(ohms) = r there for r in equation 1 gives E = 7.5 + 0.75(2) = 9V 


#2
Feb2707, 03:49 PM

P: 27

***TYPO*************Relavant Equation should be E = IR + Ir*******



Register to reply 
Related Discussions  
Question about tourists that give correct answers and wrong answers.  Set Theory, Logic, Probability, Statistics  3  
Please verify if my answers are correct.  Introductory Physics Homework  2  
Probability & QM  pls check whether my answers are correct  Calculus & Beyond Homework  7  
Organic Chemistry: are these answers correct?  Biology, Chemistry & Other Homework  1  
All solutions and answers are correct! ! !  General Discussion  47 