Question

really urgent!! plz give derivation to prove { 20 points } [class 10 physics]

#1 current in a circuit if its resistance is doubled.
#2 Resistance of a circuit if the current through it is doubled.

Answer 1

The ratio of potential difference applied between the ends of a conductor and the current flowing through it is a constant quantity called resistance.
Acc. to the Ohm's law:
. V/I = R
. V= I * R
. V/R = I
So, Current, I = V/R

It is obvious from this relation that:
1. The current is directly proportional to potential difference and
2. The current is inversely proportional to resistance

So if the resistance is doubled, the current gets halved, and

If the current is doubled the resistance gets halved.