Question

$\text{A}$ and $\text{B}$ are two conductors carrying a current $i$ in the same direction. $x$ and $y$ are two electron beams moving in the same direction. There will be

• A. repulsion between $A$ and $B$, attraction between $x$ and $y$.
• B. attraction between $A$ and $B$, repulsion between $x$ and $y$.
• C. repulsion between $A$ and $B$ and between $x$ and $y$.
• D. attraction between $A$ and $B$ and between $x$ and $y$.

Answer 1

The correct option is B attraction between $A$ and $B$, repulsion between $x$ and $y$.

The force between two parallel current carrying conductors is given as, $$F=\frac{{\mu }_0}{4\pi }\frac{I_1{I}_{2}l}{a}$$

The direction of magnetic force is indicated in the figure and is found using the right-hand thumb rule. Since, the direction of current is same , they attract each other.

$x$ and $y$ are $e^{-}$ beams, though there will be attractive magnetic force between them as $e^{-}$ beams will also behave as current carrying wires but electric force between them is repulsive as same charges (electric) repel each other.

As, Electric force $>$ magnetic force.

$x$ and $y$ will repel each other.

Hence, option (b) is the correct answer.