Question

A long straight conductor carrying a current of 2 A is in parallel to another conductor of length 5 cm and carrying a current 3 A. They are separated by a distance of 10 cm B due to first conductor at second conductor is

• A. $4\times {10}^{-6}T$
• B. $3\times {10}^{-6}T$
• C. $2\times {10}^{-6}T$
• D. $1\times {10}^{-6}T$

Answer 1

The correct option is A $4\times {10}^{-6}T$

$B=\frac{{\mu }_0{i}_1}{2\pi r_1}$

$=\frac{2\times {10}^{-7}\times 2}{10\times {10}^{-2}}$

$=4\times {10}^{-6}T$