(A): When a conducting wire loop which is inside a uniform magnetic field directed perpendicular to its planes is moving with uniform velocity, an e.m.f is induced in it.
(R) : When magnetic flux linked with a conducting wire loop changes with time an e.m.f is induced in the coil.

Options

A. A) Both .A. and .R. are true and .R. is the correct explanation of .A.
B. B) Both .A. and .R. are true and .R. is not the correct explanation of .A.
C. C) .A. is true and .R. is false
D. D) .A. is false and .R. is true

Answer

To solve the given question, we need to analyze both the assertion (A) and the reason (R) provided.

### Step 1: Understand the Assertion
The assertion states that when a conducting wire loop is inside a uniform magnetic field directed perpendicular to its plane and is moving with uniform velocity, an electromotive force (e.m.f) is induced in it.

**Analysis**:
- A uniform magnetic field means that the magnetic field strength and direction are constant throughout the area of the loop.
- When the loop moves with uniform velocity, the magnetic flux linked with the loop does not change because the field is uniform and the area of the loop remains constant.
- According to Faraday's law of electromagnetic induction, an e.m.f is induced in a loop only when there is a change in magnetic flux linked with the loop. Since the magnetic flux does not change in this case, the assertion is **false**.

### Step 2: Understand the Reason
The reason states that when the magnetic flux linked with a conducting wire loop changes with time, an e.m.f is induced in the coil.

**Analysis**:
- This statement is true. According to Faraday's law, the induced e.m.f in a circuit is directly proportional to the rate of change of magnetic flux through the circuit.
- If the magnetic flux linked with the loop changes (either due to a change in the magnetic field strength, the area of the loop, or the angle between the magnetic field and the normal to the loop), an e.m.f will indeed be induced.

### Conclusion
- The assertion (A) is **false** because there is no change in magnetic flux when the loop moves in a uniform magnetic field.
- The reason (R) is **true** because it correctly describes the condition under which an e.m.f is induced.

Thus, the final answer is that the assertion is false and the reason is true.

### Final Answer:
A is false and R is true.

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