Two straight parallel wires, both carrying 10 amp. in the same direction attract each other with a f

Question

Two straight parallel wires, both carrying 10 amp. in the same direction attract each other with a force of $10^{-3} \mathrm{~N}$. If both currents are doubled, the force of attraction will be\

Professor PC Thomas Classes · Answer

$\mathrm{F}=\frac{\mu_{0} \mathrm{I}_{1} \mathrm{I}_{2}}{2 \pi \mathrm{r}}$\ $F^{\prime}=\frac{\mu_{0}\left(2 I_{1}ight)\left(2 I_{2}ight)}{2 \pi r}$\ $\frac{\mathrm{F}^{\prime}}{\mathrm{F}}=4$\ $\mathrm{F}^{\prime}=4 \mathrm{~F}$\ $=4 	imes$\