When an alternating source of emf 24 volt is connected to a circuit containing L-R or L-C or L-C-R, current measured by an a.c. ammeter is 0.4 A. When a 24 volt d.c source is connected to the same circuit, current measured by a d.c. ammeter is 0.8 A. Then power consumed by the circuit when 24 volt alternating supply is used is