Question on ohm's law

1. Jul 18, 2015

Lim Y K

according to ohm's law, the current is proportional to the potential difference provided that the temperature remains constant. so , the for equation , R= V/I, may i know which is the constant in the equation? i know the general form of direct proportion is y=kx or y/x=k but in R=V/I, i am unable to identify which is the constant. please help me with this. thank you

2. Jul 18, 2015

davenn

hi there

There is no constant in there other than whichever one you want to remain constant

so for your example R = V/I ... if V is steady and you measure the current flowing in the circuit, you can establish the resistance present
so for any variation of those 3, from any 2 knowns, you can work out the unknown value

Dave

3. Jul 18, 2015

phinds

Why would the temperature need to remain constant? Resistance will vary with temperature but that doesn't invalidate Ohm's Law, it just means that for a fixed voltage, the current will fluctuate inversely with the resistance fluctuation

4. Jul 18, 2015

Qwertywerty

Ohm's law states that for constant physical conditions , the potential difference applied across a circuit is directly proportional to the current induced .

Or , V ∝i , and V=iR .

Thus the constant of proportionality , by ohm's law , is R .

I hope this helps .

5. Jul 18, 2015

phinds

OR, the current induced is directly proportional to the voltage applied.

6. Jul 18, 2015

Lim Y K

it does make sense to me....my notes states so as well but i just needed clarification