HC Verma: Concepts of Physics - Volume 2 Magnetic Field Due to a Current Pages 248-249: Q10 Solution: Two parallel wires carry currents of 20 A and 40 A in opposite…

QPages 248-249: Q10: HC Verma: Concepts of Physics - Volume 2 Magnetic Field Due to a Current Pages 248-249: Q10 Solution: Two parallel wires carry currents of 20 A and 40 A in opposite…

⚠️ Common Exam Traps & Conceptual Pitfalls

Students often assume that a wire placed exactly midway between two others experiences zero net magnetic force, overlooking that the force depends on both the direction (attraction vs repulsion) and the product of the currents; here the middle wire is parallel to the 40 A wire (attraction) and antiparallel to the 20 A wire (repulsion), and the larger current makes the net force towards the 40 A wire.

Two parallel wires carry currents of 20 A and 40 A in opposite directions. Another wire carrying a current anti parallel to 20 A is placed midway between the two wires. The magnetic force on it will be

Multiple Choice Options

A towards 20 A
B towards 40 A
C zero
D perpendicular to the plane of the currents

Step-by-Step Verified Solution

**Answer:** (b) towards 40 A. **Step-by-Step Explanation:** The wire with 20 A and the anti-parallel wire repel. The wire with 40 A and the anti-parallel wire also repel. The repulsion from the 40 A wire is stronger, so the net force is towards the 40 A wire.

QPages 248-249: Q10: HC Verma: Concepts of Physics - Volume 2 Magnetic Field Due to a Current Pages 248-249: Q10 Solution: Two parallel wires carry currents of 20 A and 40 A in opposite…

Multiple Choice Options

Step-by-Step Verified Solution

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