Question 183399
Let C=current, V=voltage, and R=resistance


So "The current in a wire varies directly as the voltage and inversely as the resistance" translates to {{{C=k(V/R)}}}



{{{C=k(V/R)}}} Start with the given equation



{{{C[1]=k(3V/R)}}} Triple the voltage by replacing "V" with 3V. Note: the current is now different



{{{C[1]=k(3V/2R)}}} Double the resistance by replacing "R" with 2R. Note: the current is now different



{{{C[1]=(3/2)k(V/R)}}} Rearrange the terms.



Notice how {{{k(V/R)}}} is the original expression. So we can say that the new current {{{C[1]}}} is now


{{{C[1]=(3/2)C}}}


So when the voltage triples and the resistance is doubled, the current is multiplied by {{{3/2}}} or 1.5