Answer:
4 A
Step-by-step explanation:
The relationship between current, voltage and resistance in a circuit is given by Ohm's law:
![V=RI](https://img.qammunity.org/2020/formulas/physics/high-school/golcbt5uumvr3qkkhii841o5sjv40ifo7r.png)
where
V is the voltage
R is the resistance
I is the current
The equation can also be rewritten as
![I=(V)/(R)](https://img.qammunity.org/2020/formulas/physics/high-school/59eau3i4v594xi0tdi2aoccytaiic5y1ac.png)
from which we see that the current is inversely proportional to the resistance, R.
In this problem, the initial current is I = 8 A. Then the resistance is doubled:
R ' = 2R
So the new current is
![I'=(V)/(R')=(V)/(2R)=(1)/(2)((V)/(R))=(I)/(2)=4 A](https://img.qammunity.org/2020/formulas/physics/middle-school/otj82dln33bro3xyih9a9gf5z3ay07lle2.png)
so the current is halved.