Question

The resistors R_1, R₂, R₃ and R₄ in the figure given below are all equal in value. What would you expect the voltmeters A, B and C to read assuming that the connecting wires in the circuit have negligible resistance ?

Answer 1

R_eq = R + R + R + R = 4R ohm

Total current in the circuit, I = V/R = 12/4R = 3/R

Reading of voltmeter A = Voltage across R₁ = I x R₁ = 3/R x R = 3V

Reading of voltmeter B = Voltage across R₂ = I x R₂ = 3/R x R = 3V

Reading of voltmeter C = Voltage across the series combination of R₃ and R₄ = Ix(R₃ + R₄) = 3/R x 2R = 6V