1 kg piece of copper is drawn into a wire of 1 mm thickness, and another 1 kg copper piece into a wire of 2 mm thickness. What is the ratio of the resistance of these two wires respectively?

Q. Nichrome and copper wires of same length and same radius are connected in series. Current I is passed through them. Which wire gets heated up more ? Justify your answer

Join BYJU'S Learning Program

If two wires 1 mm and 2 mm thick are made of same mass of copper connected in series and current is passed through them, then heat produced in the wires is in the ratio.

The correct option is C 16:1Heat produced, H=i2RT=i2(ρlπ)t=i2ρVtA2(∵Al=V)H∝1r4So, H1H2=(r2r1)4=(21)4=161.

If two wires $1 m m$ and $2 m m$ thick are made of same mass of copper connected in series and current is passed through them, then heat produced in the wires is in the ratio.

The correct option is C $16 : 1$
Heat produced, $H = i^{2} R T = i^{2} (\frac{ρ l}{π}) t$
$= \frac{i^{2} ρ V t}{A^{2}} (∵ A l = V)$
$H \propto \frac{1}{r^{4}}$
So, $\frac{H_{1}}{H_{2}} = {(\frac{r_{2}}{r_{1}})}^{4} = {(\frac{2}{1})}^{4} = \frac{16}{1}$ .