Answer: 6 A
Step-by-step explanation:
Given
Current varies directly with Voltage
i.e.
[tex]I\ \propto V\ or\\V\ \propto\ I\\V=IR[/tex]
when V=12 V, I=4 A i.e.
[tex]\Rightarrow 12=4R\\\Rightarrow R=3\ \Omega[/tex]
When V=18 V
[tex]\Rightarrow 18=I\times 3\\\Rightarrow I=6\ A[/tex]
Current is 6 Ampere