In the figure shown a current I1 is established in the long straight wire AB. Another wire CD carrying current I2 is placed in the plane of the paper. The line joining the ends of this wire is perpendicular to the wire AB. The force on the wire CD is:

Engineering

Physics

Magnetic Field

Biot Savart Law

Magnetic Force on a Current Carrying Wire

Question

In the figure shown a current I₁ is established in the long straight wire AB. Another wire CD carrying current I₂ is placed in the plane of the paper. The line joining the ends of this wire is perpendicular to the wire AB. The force on the wire CD is:

directed upwards

towards left

none of these

zero

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The force on wire CD depends on the magnetic field created by wire AB and the current in CD. The magnetic field around a long straight wire (AB) is circular, given by $B = \frac{μ_{0} I_{1}}{2 π r}$ . For wire CD, which is perpendicular to AB, the magnetic field is parallel to the wire along its entire length. The force on a current-carrying wire is $\vec{F} = I (\vec{l} \times \vec{B})$ . Since $\vec{l}$ and $\vec{B}$ are parallel for CD, the cross product is zero, resulting in no net force.

Final Answer: zero