Consider the circuit shown in the figure(Figure 1) . Suppose the four resistors
ID: 1655013 • Letter: C
Question
Consider the circuit shown in the figure(Figure 1) . Suppose the four resistors in this circuit have the values R1 = 13 , R2 = 7.6 , R3 = 6.9 , and R4 = 15 , and that the emf of the battery is E = 18 V .
Part A
Find the current through each resistor using the rules for series and parallel resistors.
Express your answers using two significant figures separated by commas.
Part B
Find the current through each resistor using Kirchhoff's rules.
Express your answers using two significant figures separated by commas.
w 2 3 4Explanation / Answer
R2 and R4 are in series and their combination is given as
R24 = R2 + R4 = 7.6 + 15 = 22.6 ohm
R24 and R3 are in parallel and their combination is given as
R243 = R24 R3/(R24 + R3)
R243 = 22.6 x 6.9/(22.6 + 6.9) = 5.3 ohm
total current coming from the battery is given as
i = E/(R243 + R1) = 18/(5.3 + 13) = 0.98 A
i1 = i = 0.98 A
V3 =E - V1 = E - i1R1 = 18 - (0.98) (13) = 5.3 volts
i3 = V3/R3 = 5.3 /6.9 = 0.77 A
i2 = i4 = i1 - i3 = 0.98 - 0.77 = 0.21 A