Thévenin’s Theorem?

Since there is no potential drop across the 10 k-ohm resistance when the load resistance RL is removed, the Thevenin voltage (i.e. the potential at point a) is the voltage across the 24 k-ohm resistance.

Hence, Thevenin voltage = 48 x [24/(16 + 24)] v = 28.8 v

The Thevenin resistance is the resistance equivalent to the 10 k-ohm resistance in series with the 16 k-ohm and 24 k-ohm resistances in parallel.

Hence, Thevenin resistance
= 10 + [16 x 24/(16+24)] k-ohms
= 19.6 k-ohms

Therefore, the Thevenin equivalent circuit is a voltage source of 28.8 v in series with a resistance of 19.6 k-ohms.