A: Magnetic field lines can be entirely confined within the corre of a toroid.
R: Magnetic field lines cannot be entirely confined within the corer of a straight sotenoid.

Options

A. If both Assertion & Reason are the true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reson is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To analyze the given statements, we need to evaluate both the assertion (A) and the reason (R) regarding magnetic field lines in a toroid and a straight solenoid.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "Magnetic field lines can be entirely confined within the core of a toroid."
- A toroid is a doughnut-shaped coil of wire, and when current flows through it, the magnetic field lines form closed loops around the core.
- Inside the toroid, the magnetic field lines are concentrated and do not extend outside the toroidal shape. Therefore, the assertion is **correct**.

2. **Understanding the Reason (R)**:
- The reason states that "Magnetic field lines cannot be entirely confined within the core of a straight solenoid."
- A straight solenoid is a long coil of wire where, when current flows, magnetic field lines are generated.
- Inside the solenoid, the magnetic field lines are indeed concentrated, but they also extend outside the solenoid. This means that the magnetic field lines are not entirely confined within the core, making the reason **correct** as well.

3. **Conclusion**:
- Both the assertion and the reason are correct statements. The assertion accurately describes the behavior of magnetic field lines in a toroid, while the reason correctly explains the behavior in a straight solenoid.
- Therefore, the answer to the question is that both statements are true.

### Final Answer:
Both the assertion (A) and the reason (R) are correct.

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