Physics – 4.3.2 Series and parallel circuits | e-Consult

Solution:

1. Calculate the equivalent resistance of the parallel combination:

   1/R_eq = 1/R + 1/R + 1/R

   1/R_eq = 1/10Ω + 1/20Ω + 1/20Ω

   1/R_eq = 2/20Ω + 1/20Ω + 1/20Ω = 4/20Ω = 1/5Ω

   R_eq = 5Ω

2. The student states the equivalent resistance is 4Ω. This is incorrect. The correct equivalent resistance is 5Ω.
3. Calculate the total current (I_total) from the battery using Ohm's Law:

   I_total = V / R_eq

   I_total = 6V / 5Ω = 1.2 A

Answers: The equivalent resistance is 5Ω, not 4Ω. Total current = 1.2 A