Question

Two parallel conductors carry current in opposite directions as shown in figure. One conductor carries a current of 10.0 A. Point C is a distance \( \frac{d}{2} \) to the right of the 10.0 A current. If \( d = 18 \, \text{cm} \) and \( I \) is adjusted so that the magnetic field at C is zero, the value of the current \( I \) is
\includegraphics[width=0.35\linewidth]30.png

• A. 10.0 A
• B. 30.0 A
• C. 8.0 A
• D. 18.0 A

Hint:

When dealing with magnetic fields due to currents, use Ampère’s law to find the current required to cancel out the field at a given point.

Answer 1

The Correct Option is B

Step 1: Use Ampère’s law.
The magnetic field at point C due to the two currents must cancel each other out for the total magnetic field to be zero.
Step 2: Calculate the current \( I \).
By equating the magnetic fields due to both currents, we solve for \( I = 30.0 \, \text{A} \). Final Answer: \[ \boxed{30.0 \, \text{A}} \]