Consider the circuit shown in the figure below. (Assume R 1 = 12.0 , R 2 = 2.20
ID: 1377817 • Letter: C
Question
Consider the circuit shown in the figure below. (Assume R1 = 12.0 , R2 = 2.20 , andV = 6.00 V.)
(a) Calculate the equivalent resistance of the R1 and 5.00- resistors connected in parallel.
(b) Using the result of part (a), calculate the combined resistance of theR1, 5.00- and 4.00- resistors.
(c) Calculate the equivalent resistance of the combined resistance found in part (b) and the parallel 3.00- resistor.
(d) Combine the equivalent resistance found in part (c) with the R2 resistor.
(e) Calculate the total current in the circuit.
A
(f) What is the voltage drop across the R2resistor?
V
(g) Subtracting the result of part (f) from the battery voltage, find the voltage across the 3.00- resistor.
V
(h) Calculate the current in the 3.00-resistor.
A
Explanation / Answer
since R1 and 5 ohm resistor are parallel so
1/Req = 1/5 + 1/R1
1/Req = 1/5 + 1/12
a) Req = 3.5294 ohm
since 4 ohm resistor is in series with Req
so,
Req1 = Req + 4
Req1 = 3.5294 + 4
b) Req1 = 7.5294 ohm
since Req1 and 3 ohm resistor are parallel
so,
1/Req2 = 1/Req1 + 1/3
1/Req2 = 1/7.5294 + 1/3
c) Req2 = 2.14525 ohm
since Req2 and R2 are in series so,
Req3 = Req2 + R2
Req3 = 2.14525 + 2.2
d) Req3 = 4.34525 ohm
by ohm's law
V = I R
6 = I * 4.34525
I = 1.381 A
e) total current in the circuit = 1.381 A
voltage drop aross R2 = I * R2
Vdrop = 1.381 * 2.2
f) voltage drop aross R2 = 3.0382 V
voltage across the 3.00-? resistor = 6 - 3.0382
g) voltage across the 3.00-? resistor = 2.9618 V
current in the 3.00-?resistor = 2.9618 / 3
h) current in the 3.00-?resistor = 0.9873 A