Calculate the voltmeter reading (in V) for the resistor network shown. The source is 10 V; the voltmeter has resistance 1200 Ω. Other resistors: 100 Ω, 100 Ω, 800 Ω, 200 Ω and 600 Ω. [See Image.]
Physics · Mixed Chapter
JEE Main Practice

Question

Calculate the voltmeter reading (in V) for the resistor network shown. The source is 10 V; the voltmeter has resistance 1200 Ω. Other resistors: 100 Ω, 100 Ω, 800 Ω, 200 Ω and 600 Ω. [See Image.]

Physics · Mixed Chapter

G1 Physics · Accepted Answer

Step 1 — Assign the right battery terminal potential 0 and left terminal 10 V. Let the two internal junction potentials be V₁ and V₂. Step 2 — Apply Kirchhoff current law: (V₁−10)/100 + (V₁−V₂)/100 + V₁/600 + V₁/1200 = 0; and (V₂−10)/200 + (V₂−V₁)/100 + V₂/800 = 0. Step 3 — Solve these simultaneous linear equations: V₁ = 8 V and V₂ = 8 V. Step 4 — The voltmeter is across V₁ and the right terminal; its reading is 8 V.