In the circuit shown R₁ = 10 ohm R₂ = 20 ohm R₃ = 30 ohm And the potentials of points A, B and C are 10V, 6V and 5V respectively The current though resistance R₁ is

0.2A

             10l₁ + 20l₂ = 10 –6 = 4                                                  … (1)

            10l₁ + 30(l₁ – l₂) = 5

            or   40 l₁  – 30 l₂ = 5                                        … (2)

            Solving for l₁,

            We get l₁ = 0.2A