The answer is 2 times.
In parallel DC circuit the power (P) can be calculated by using the values of total current (I) and resistance (R):
P = I²R
The old power is:
Po = Io² x Ro
Io = 4 A
Ro = 0.5 ohms (Ω)
So, Po = 4² A x 0.5 Ω = 8 W
The new power is:
Pn = In² x Rn
In = 4 A x 2 = 8 A
Rn = 0.5 Ω ÷ 2 = 0.25 Ω
So, Po = 8² A x 0.25 Ω = 16 W
Pn ÷ Po = 16 W ÷ 8 W = 2
Thus, the new power is 2 x higher than the old power.
