Statement-1 : Earthquakes cause vast devastation. Sometimes short and tall structures remain unaffected while the medium height structures fall
Statement-2 : The natural frequency of the medium structures coincides with the frequency of the seismic wave.

Options

A. Statement-1 is true, Statement-2 is true , Statement-2 is correct explanation for Statement-12
B. Statement-1 is true,Statement-2 is true , Statement-2 is NOT a correct explanation for Statement-12
C. Statement-1 is true, Statement-2 is false
D. Statement-1 is false, Statement-2 is true

Answer

To analyze the given statements, we will break down the reasoning step by step.

### Step 1: Understanding Statement 1
**Statement 1**: Earthquakes cause vast devastation. Sometimes short and tall structures remain unaffected while the medium height structures fall.

**Explanation**: This statement highlights the varying impacts of earthquakes on structures of different heights. Short and tall buildings may withstand seismic waves better than medium-height structures.

### Step 2: Understanding Statement 2
**Statement 2**: The natural frequency of the medium structures coincides with the frequency of the seismic wave.

**Explanation**: This statement refers to the concept of resonance. Every structure has a natural frequency at which it tends to vibrate. When the frequency of seismic waves matches the natural frequency of a medium-height structure, resonance occurs, leading to larger amplitude vibrations and potential collapse.

### Step 3: Analyzing the Relationship Between the Statements
- **Resonance Phenomenon**: When the frequency of seismic waves matches the natural frequency of a medium-height building, it causes the building to oscillate with larger amplitudes. This can lead to structural failure.
- **Impact on Different Structures**: Short buildings are typically affected by high-frequency waves, while tall buildings respond to low-frequency waves. Medium-height buildings are uniquely vulnerable because their natural frequency can align with the frequencies of seismic waves.

### Step 4: Conclusion
- **Validity of Statements**: Both statements are true. Statement 2 provides a correct explanation for why medium-height structures are more likely to fall during an earthquake, as they resonate with the seismic waves.

### Final Answer
Both Statement 1 and Statement 2 are true, and Statement 2 is the correct explanation for Statement 1.

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