Question

The pattern of the magnetic field produced by the straight current carrying conducting wire is:

• A. in the direction opposite to the current
• B. in the direction parallel to the wire
• C. circular around the wire
• D. in the same direction of current

Hint:

Remember Maxwell's Right-Hand Thumb Rule:
Thumb = Direction of current (\(I\)).
Curled Fingers = Direction of magnetic field lines (\(B\)).
The field lines always form concentric closed loops.

Answer 1

The Correct Option is C

Step 1: Recall the iron filings experiment.
If you sprinkle iron filings on a card with a current carrying wire through it and tap gently, the filings arrange themselves in closed loops centred on the wire.
Step 2: Interpret this pattern.
Each closed loop is a magnetic field line, and because they form full circles around the wire lying in a plane perpendicular to it, we say the field has a circular shape.
Step 3: Confirm with the right hand rule.
Curling the right hand fingers around the wire with the thumb pointing along the current shows the fingers tracing out these same circular paths, which matches what the filings show.
\[ \boxed{\text{Circular around the wire}} \]