Question

For a circular coil carrying current, the thumb in the right hand thumb rule gives the direction of

• A. magnetic field
• B. current
• C. induced emf
• D. electric field
• E. electric force

Hint:

Right hand thumb rule: thumb → current direction (straight wire), curled fingers → magnetic field. For coils, thumb gives magnetic field direction.

Answer 1

The Correct Option is A

Step 1: Recall the right hand thumb rule.
The right hand thumb rule states that if we hold a current carrying conductor in the right hand such that the thumb points in the direction of current, then the curled fingers represent the direction of the magnetic field lines.

Step 2: Apply the rule to a circular coil.
For a circular coil, the current flows in a loop. When we curl the fingers in the direction of current, the thumb points perpendicular to the plane of the coil.

Step 3: Interpret the thumb direction.
The thumb gives the direction of the magnetic field inside the loop (along the axis of the coil).

Step 4: Distinguish from other quantities.
The rule does not give direction of current (that is already known), nor does it relate to electric field, induced emf, or force.

Step 5: Connect with physical understanding.
The magnetic field lines around a current carrying coil resemble those of a bar magnet, and the thumb indicates the direction of the field.

Step 6: Match with options.
Thus, the thumb indicates the direction of magnetic field.

Step 7: Final answer.
\[ \boxed{\text{magnetic field}} \] which matches option \((1)\).