Question

In the given figure, the directions of induced current in a square loop as it enters and leaves a uniform magnetic field respectively are

• A. Counter clockwise, Clockwise
• B. Clockwise, Counter clockwise
• C. Counter clockwise, Counter clockwise
• D. Clockwise, Clockwise

Hint:

Use Lenz's law: \[ \boxed{\text{Induced current always opposes the change in magnetic flux}.} \] Also remember: \[ \boxed{ \begin{aligned} \text{Counter clockwise current} &\Rightarrow \text{Field out of the page}, \text{Clockwise current} &\Rightarrow \text{Field into the page}. \end{aligned} } \]

Answer 1

The Correct Option is A

Step 1: Identify the direction of the magnetic field. The crosses (\(\times\)) indicate that the magnetic field is directed \[ \boxed{\text{into the plane of the paper}.} \]

Step 2: Apply Lenz's law when the loop enters the field. As the loop enters the magnetic field, the magnetic flux into the page increases. According to Lenz's law, the induced current opposes this increase by producing a magnetic field out of the page. Using the right-hand thumb rule, this requires a \[ \boxed{\text{counter clockwise current}.} \]

Step 3: Apply Lenz's law when the loop leaves the field. As the loop leaves the magnetic field, the magnetic flux into the page decreases. To oppose this decrease, the induced current must produce a magnetic field into the page. By the right-hand thumb rule, this requires a \[ \boxed{\text{clockwise current}.} \] Hence, \[ \boxed{\text{Counter clockwise, Clockwise}.} \] Therefore, the correct option is \(\boxed{(A)}\).