Solve the previous question if the closed loop is completely enclosed in the circuit containing the switch.

A. a clockwise current-pulse
B. an anticlockwise current-pulse
C. an anticlockwise current-pulse and then a clockwise current-pulse
D. a clockwise current-pulse and then a clockwise current-pulse

Options

A. a clockwise current-pulse
B. an anticlockwise current-pulse
C. an anticlockwise current-pulse and then a clockwise current-pulse
D. a clockwise current-pulse and then a clockwise current-pulse

Explanation

To solve the problem, we need to analyze the situation where a closed loop is completely enclosed within a circuit that contains a switch. We will follow these steps:

### Step 1: Understand the Setup
- We have a closed loop completely enclosed in a circuit with a switch.
- The current in the circuit is flowing in a specific direction (let's assume it is clockwise).

**Hint:** Visualize the circuit and the closed loop, and note the direction of the current flow.

### Step 2: Determine the Magnetic Field Direction
- According to the right-hand rule, if the current is flowing in a clockwise direction, the magnetic field lines will be directed downwards (into the page) at the center of the loop.

**Hint:** Use the right-hand grip rule to determine the direction of the magnetic field based on the current flow.

### Step 3: Analyze the Change in Current
- If the switch is closed, the current in the circuit may either increase or decrease. In this case, we assume that the current is decreasing.

**Hint:** Consider how the change in current affects the magnetic field and the magnetic flux through the loop.

### Step 4: Apply Faraday's Law of Electromagnetic Induction
- According to Faraday's Law, a change in magnetic flux through the loop induces an electromotive force (emf) in the loop.
- Since the current is decreasing, the magnetic flux through the loop is also decreasing.

**Hint:** Recall that a decreasing magnetic flux will induce a current in the loop in such a way as to oppose the change (Lenz's Law).

### Step 5: Determine the Direction of Induced Current
- To oppose the decrease in magnetic flux, the induced current must flow in a direction that will create a magnetic field to increase the flux.
- Since the original magnetic field is directed downwards (into the page), the induced current must flow in an anticlockwise direction to create an upward magnetic field (out of the page).

**Hint:** Use Lenz's Law to determine the direction of the induced current based on the change in magnetic flux.

### Conclusion
- Thus, the induced current in the closed loop will flow in an anticlockwise direction.

**Final Answer:** B. an anticlockwise current-pulse.