SSC JE Electrical Engineering 2012 Paper

The Thevenin equivalent resistance ${\mathit{R}}_{\mathit{s}}$ is viewed from the open terminals. A and B is given as per Thevenin theorem, when resistance ${\mathit{R}}_{\mathit{L}}$ is connected across terminals A and B, the network behaves as a source of voltage ${\mathit{V}}_{\mathit{s}}$ and internal resistance RT and this is called Thevenin equivalent circuit.