Shown in the figure below are the potential differences across four resistors in

Question

Shown in the figure below are the potential differences across four resistors in a series circuit. Rank the resistances of the resistors. Explain including data from past investigations to support your ranking. What is the potential difference of the battery? How do you know? (Again your explanation should reference data from previous investigations.) The figure at the right shows the same four resistors connected in a parallel circuit with the same battery as above. Take the current from the battery I_p as 400 mA. What is potential difference across each resistor? How do you know? What is the current through each of the resistors? How do you know?

Explanation / Answer

Here

1) as the current through all the resistances will be same in series

as V = I * R

R = V/I

hence , the rank of resistances is

C > B > A > D

20

let the potential differnce of battery is E

E = A + B + C + D

E = 4 + 8 + 9 + 3

E = 24 V

the potential difference of the battery is 24 V

this is using Kirchoff's voltage rule.

3)

for the same battery

the potential acorss the resistances will be same

potential across each resistor = 24 V

4)

let the currents are 4R , 8R , 9R , 3R

for the current through each resistance

1/Req = 1/(4R) + 1/(8R) + 1/(9R) + 1/(3R)

Req = 1.220 *R

Now, 24 = 1.220 * R * 0.400

R = 49.2 Ohm

current through A = (24/(4 * 49.2)) = 0.122 A

current through B = (24/(8 * 49.2)) = 0.061 A

current through C = 24/(9 * 49.2) = 0.054 A

current through D = 24/(3 * 49.2) = 0.163 A

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.