Read the following two statements.
(A) Emf can be induced by changing magnetic field.
(B) Emf must be induced when a conductor is moved inside magnetic field.

Options

A. Both A and B are true.
B. A is true but Bis false.
C. B is true and A is false
D. Both A and B are false.

Explanation

To analyze the two statements regarding electromagnetic induction, we will evaluate each statement based on the principles of electromagnetism.

### Step-by-Step Solution:

1. **Understanding Statement A**:
- Statement A claims that "Emf can be induced by changing magnetic field."
- According to Faraday's Law of Electromagnetic Induction, an electromotive force (emf) is induced in a circuit when there is a change in the magnetic flux through the circuit. This means that if the magnetic field changes (either in strength or direction), an emf will be induced.
- Therefore, Statement A is **True**.

2. **Understanding Statement B**:
- Statement B states that "Emf must be induced when a conductor is moved inside a magnetic field."
- While it is true that moving a conductor through a magnetic field can induce an emf (as per Faraday's Law), it is not the only way to induce an emf. An emf can also be induced by changing the magnetic field around a stationary conductor.
- The use of the word "must" in Statement B implies that it is the only condition for inducing emf, which is incorrect. Thus, Statement B is **False**.

3. **Conclusion**:
- Based on the evaluation, we conclude that:
- Statement A is True.
- Statement B is False.
- Therefore, the correct answer is that A is true and B is false.

### Final Answer:
- A is True, B is False.