When a 27.0-V emf device is placed across two resistors in series, a current of
ID: 1340319 • Letter: W
Question
When a 27.0-V emf device is placed across two resistors in series, a current of 12.0 A is flowing in each of the resistors. When the same emf device is placed across the same two resistors in parallel, the current through the emf device is 54.0 A. What is the magnitude of the larger of the two resistances?Tries 0/10 When a 27.0-V emf device is placed across two resistors in series, a current of 12.0 A is flowing in each of the resistors. When the same emf device is placed across the same two resistors in parallel, the current through the emf device is 54.0 A. What is the magnitude of the larger of the two resistances?
Tries 0/10 Tries 0/10
Explanation / Answer
Given that
When a 27.0-V emf device is placed across two resistors in series, a current of 12.0 A is flowing in each of the resistors.
Then R resistance of the circuit is given by ohms law V =IR
Then R =V/I =27/12 =2.25ohms
When the same emf device is placed across the same two resistors in parallel, the current through the emf device is 54.0 A
Again using the ohms law we can find the ressitance of the circuit in parallel then
R =V/I =27/54 =0.5A
The equivalent resistance in series is given by
Req =R1+R2 =2.25 ===> R1 =2.25-R2
The equivalent resistance in parallel is given by
1/Req =1/R1+1/R2
1/0.5 =1/(2.25-R2)+1/R2
Now solve the quadratic equation you will get R2 then we know that
2.25 =R1+R2
R1 =2.25-R2 you will get R1
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.