Question

Resistance of a conductor is reduced to half its initial value, then heat generated in the conductor will become

• A. half.
• B. double.
• C. one-fourth.
• D. four times.

Answer 1

The correct option is B double.

There are lot of formula to find heat produced in the conductor.

$P=I^2,P=VI,P=\frac{V^2}{R}$

which one should be used ? confusion ?

Don't be confuse dud , just use $P=\frac{V^2}{R}$

because here question didn't say about altering of voltage. means, voltage remains same. hence, we should Power $=\frac{V^2}{R}$

now tell me , when resistance of a conductor is reduced to half , then power should be ?

of course , double

because power is inversely proportional to resistance , if resistance is reduced to haft then power will be double.

hence, the power is doubled.