Norton equivalent between A and B for the circuit shown in Fig. 1 is

The Norton equivalent circuit consists of a current source ($I_N$) in parallel with a resistance ($R_N$). The values of $I_N$ and $R_N$ are determined by analyzing the original circuit. $R_N$ is the equivalent resistance seen from the terminals with independent sources deactivated. $I_N$ is the current flowing through the terminals when they are short-circuited.