Problem 19.30 (Question 6 in 2A) Calculate the currents in each resistor of the
ID: 1455918 • Letter: P
Question
Problem 19.30 (Question 6 in 2A)
Calculate the currents in each resistor of the figure. (Figure 1)
Part A
Calculate the current in 25 ? resistor.
Express your answer to two significant figures and include the appropriate units.
Part B
Calculate the current in 120 ? resistor.
Express your answer to two significant figures and include the appropriate units.
Part C
Calculate the current in 64 ? resistor.
Express your answer to two significant figures and include the appropriate units.
Part D
Calculate the current in 110 ? resistor.
Express your answer to two significant figures and include the appropriate units.
Part E
Calculate the current in 82 ? resistor.
Express your answer to two significant figures and include the appropriate units.
*Please Be Clear and logical in your Typing/Picture. Specifically, I am having trouble with the solving method so kindly detail with an explantion.This is a Exam Question for me. I will return the favor with rate and comment :)
Explanation / Answer
Combine the 120 and 82 resistors into one R = 202 resistor.
Combine the 25 and 110 resistors into one R = 135 resistor located where the 25 resistor was.
Call the remaining 64 resistor as R, just for kicks.
Set the (-) terminal of the +3V to GND (0V.) Swap the series positions of V = -58V supply and R.
Circuit is much simpler, now.
There's only one unknown node value! Call it Vx. And only three remaining resistors.
Using nodal analysis on that node:
Vx R + Vx R + Vx R = -58 R + 3V R + GND R
Vx 202 + Vx 135 + Vx 64 = -58 202 + 3V 135 + 0V 64
Vx(¹ + ¹ + ¹) = -¹²
Vx -9.46673V
So, now you can answer the questions.
The current in R will be the same as the current in the 120 and the 82 resistors.
The current in R will be the same as the current in the 25 and 110 resistors.
The current in R is the current in the 64 resistor.
(a) (Vx - 3V) R = (-9.46673V - 3V) 135 -92.346mA
(b) (Vx - -58V) R = (-9.46673V - -58V) 202 240.264mA
(c) (Vx - GND) R = (-9.46673V - 0V) 64 -147.918mA
(d) same as (a), so: -92.346mA
(e) same as (b), so: 240.264mA
The signs above reflect the "direction" of the current from the point of view of Vx. + means outward, - means inward.