Question

A circuit with a resistance of `9 Omega` has a fuse melts at `6 A`. Can a voltage of `12 V` be applied to the circuit without blowing the fuse?

Answer 1

Yes; the current produced (`1 1/3 Amperes`) is less than the maximum permitted by a `6A` fuse.

Explanation:

`12V` applied to a circuit with a resistance of `9Omega`
will generate `(12V)/(9Omega) = 4/3 Amps` of current.

I like to think of it in the form
`color(white)("XXX")"Current" = ("Voltage")/("Resistance")`
since it seems obvious to me that increasing the voltage should increase the current and increasing the resistance should decrease the current.

However some people prefer:
`color(white)("XXX")"Voltage" = "Current"xx"Resistance"`
or
`color(white)("XXX")("Voltage")/("Current"xx"Resistance")=1` (there is even a diagram for this)