Question

S waves travel from the focus of the earthquake through {

• A. A Only
• B. B Only
• C. A and B Only
• D. A and C Only

Hint:

Remember: P-waves pass through solids, liquids, and gases. S-waves pass only through solids.

Answer 1

The Correct Option is A

Concept: Earthquake waves are mainly of two body-wave types: P-waves and S-waves. P-waves can travel through solids, liquids, and gases, but S-waves can travel only through solids.

Step 1: Understand S-waves.
S-waves are secondary waves. They move the ground perpendicular to the direction of wave travel. \[ S\text{-waves} = \text{Shear waves} \]

Step 2: Understand why S-waves cannot travel through liquids.
S-waves need rigidity or shear strength to travel. Liquids and gases do not have enough shear strength. \[ \text{Liquids and gases} \Rightarrow \text{No shear rigidity} \]

Step 3: Select the correct medium.
Since S-waves travel only through solid parts of the Earth, option A is correct. \[ S\text{-waves} \rightarrow \text{Solid medium only} \] Therefore, the correct answer is A Only.