Question

f you double the voltage in a circuit and reduce the resistance by a factor of four, what will happen to the current?

Answer 1

Current will be double..

Answer 2

this depends upon whether Ohms law applies. Ohms Law is an empirical observation, much in the same same way that π is known to be the ratio of the circumference of a circle to its diameter. it is a result of experiment. materials obeying the law are said to be Ohmic.

Ohms Law sates that V = IR. that is to say, voltage = current * resistance.

this gives I = V/R

if you double V and reduce R by a factor of 4, you get the following;

I = 2V/(R/4)

so, I = 8V/R

you will get a 8x increase in current.

there are a billion assumptions in this rely.

you might have capacitors in the circuit, you might be talking about AC and have transformers and all sorts of stuff going on. it is assumed that you are talking about a simple DC cell with a simple Ohmic resistor.

does this help?

Answer 3

you already have your answer