Question 249: Magnetism and Matter

Question

Two long conductors, separated by a distance $$d$$ carry current $${I_1}$$ and $${I_2}$$ in the same direction. They exert a force $$F$$ on each other. Now the current in one of them is increased to two times and its direction is reversed. The distance is also increased to $$3d$$. The new value of the force between them is

Accepted Answer

Force between two long conductor carrying current,
$$F = {{{\mu _0}} \over {4\pi }}{{2{I_1}{I_2}} \over d} 	imes \ell $$
$$F' =  - {{{\mu _0}} \over {4\pi }}{{2\left( {2{I_1}} ight){I_2}} \over {3d}}\ell $$
$$	herefore$$ $${{F'} \over F} = {{ - 2} \over 3}$$

Answer

$$ - {{2F} \over 3}$$

Answer

$${F \over 3}$$

Answer

$$-2F$$

Answer

$$ - {F \over 3}$$

Magnetism and Matter

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