Statement-1 : in standing wave average rate of transfer of energy at any cross-section is zero.
because
Statement-2 : instantaneous rate of energy transfer at node is equal to zero.

Options

A. Statement -1 is True, statement -2 is True, Statement -2 is a correct explanation for Statement -1.
B. Statement -1 is True, Statement -2 is True , Statement-2 is Not a correct explanation for statement-9
C. Statement -1 is True, statement -2 is False
D. Statement -1 is False, Statement -2 is True.

Answer

To analyze the statements provided in the question, we need to understand the concepts of standing waves and energy transfer.

### Step-by-Step Solution:

1. **Understanding Standing Waves**:
- A standing wave is formed by the interference of two waves traveling in opposite directions. It consists of nodes (points of no displacement) and antinodes (points of maximum displacement).

2. **Average Rate of Energy Transfer**:
- In a standing wave, the average rate of energy transfer at any cross-section is indeed zero. This is because the energy does not propagate through the medium; instead, it oscillates in place. The energy is stored in the wave and does not move from one point to another.

3. **Instantaneous Rate of Energy Transfer at Nodes**:
- At the nodes of a standing wave, the particles of the medium do not move; they remain at rest. Therefore, the instantaneous rate of energy transfer at these points is also zero. The energy oscillates between kinetic and potential forms, but there is no net transfer of energy at the nodes.

4. **Conclusion**:
- Since both statements are true:
- Statement 1 is true because the average rate of energy transfer in a standing wave is zero.
- Statement 2 is true because the instantaneous rate of energy transfer at the nodes is also zero.
- Thus, both statements are correct.

### Final Answer:
Both Statement-1 and Statement-2 are true.