ljcox said:
I don't understand tour reasoning. You appear to have just juggled the figures until you got the answer.
at first this what I did, I had to , I'm teaching myself ( although I do have access to tutors , during the week , but not on weekends , and I wanted to take the exam on this module on sunday night , therefore I had to figure it out , by juggling the numbers) but I also tried to reason it out.
since there is a short , and therefore one less resistor , which therefore leads to an increase in current and therefore power which each of the remaining resistors had to dissipate.
so you had to ADD additional power to the original power quantity.
which both methods do. its just that the method I chose is faster.
let me ask you a question that came up last night.
how would you approach this question;
you have 2 resistors, R1 has a resistance of 650ohms, R2 ? (is unknown)
the total resistance is 250ohms. its a parallel circuit. what equation(s) would you use to solve this problem? this how I did it ;
1/250-1/650=1/R2, then to get R2 alone I divided the answer on the right side by 1 to get rid of the 1 over R2.( which changes nothing on the right). I got the right answer. do you find a problem with my above method that I used here?
one of my tutors , who returned my call from last night , used the " product over sum rule " equation.
( I couldn't ask my tutors last night because a snowstorm shut down the college. so I had to figure it out on my own.)
anybody else of course can suggest their approach as well!! and please do.
ljcox said:
Could you have done it if you did not know the answer?
yes I could've and did to a point I just didn't go far enough and added the answer of 20/3 to the original power quantity and divide by 3 again. but being a student and learning I didn't have the confidence in what I was doing.