As far as we know that theorems help in solving circuits easily. The simplification of any circuit can be done using network theorems. Among them, one of the important theorems is Norton’s Theorem. The circuits can be solved and simplified to find out the required quantity i.e., current, voltage, or resistance, using Norton’s Theorem.

Yes Norton’s Theorem can be applied to both AC and DC circuits.

As Norton’s Equivalent circuit itself is obtained by connecting a current source in parallel to the resistance, and it is easy to solve the circuits using Nortons theorem when All voltage sources shorted and all the current sources open-circuited leaving behind their internal resistances

Thevenin's and Norton's circuits can be transformable as the Equivalent circuit has a change with the source i.e., voltage or current in series or parallel to the Resistance

Norton’s Theorem is the converse of Thevenin’s Theorem. We know that \(V_L=(\frac{V_{Th}}{R_{Th}+R_L})R_L\) in Thevenin’s and in Norton’s Theorem \(I_{L}=I_N\frac{R_{N}}{R_{N}+R_L}\) this is almost similar to the \(I_L=\frac{V_{Th}}{R_{Th}+R_L}\) in Thevenin’s Theorem