Concepts Of Physics MCQ Edition [Volume 2]PhysicsMagnetic Field due to a Current
Two long, straight wires are positioned along the x - and y -axes, respectively, with each carrying a current of 5 A . The currents are directed along the positive directions of the axes. Determine the magnetic field at the point (1 m , 1 m ) .
Options
- A2 T along the negative z -axis
- B1 T along the positive z -axis
- C2 T along the positive z -axis
- DZero
Correct answer
D. Zero
Step-by-step solution
The magnetic field due to a long straight wire carrying current I at a perpendicular distance d is given by B = ₀ I 2 d . For the wire along the x -axis carrying current in the positive x -direction, the magnetic field at (1 m , 1 m ) is directed along the positive z -axis (using the right-hand thumb rule). B ₁ = ₀ I 2 y k = 4 10⁻⁷ 5 2 1 k = 10⁻⁶ k T = 1 T k For the wire along the y -axis carrying current in the positive y -direction, the magnetic field at (1 m , 1 m ) is directed along the negative z -axis. B ₂ =