Question

In an electrical circuit, the current passing through a conductor varies inversely with the resistance. Suppose that when the current is
3 A (amperes), the resistance is
40ohms. What is the current when the resistance is 15 ohms?

Answer 1

Ohm's law
\[V=IR\]
where V is voltage in volts
where I is current in amps
where R is resistance in ohms

Answer 2

Recall an inverse relationship , Y is inversely proportional to X
\[\large y~~~\alpha~~~\frac{ 1 }{ x }\]
insert a constant value k to make an equation, current y varies inversely with the resistance x.
\[\large y=\frac{ k }{ x }\]

Answer 3

The data point they give you allows you to figure out the value of the constant k..
If current Y=3, then the resistance is x=40

3=k/40
k=120

so the equation is
\[\large y=\frac{ 120 }{ x }\]

Answer 4

for the resistance is instead now x=15 ohms, you can calculate the current

Answer 5

Im getting 8 amperes? is that right?

Answer 6

yes

Answer 7

TY :)