Read the assertion and reason carefully to mark the correct option ou...
Ocean waves are transverse waves travelling in concentric circles of ever increasing radius. When they hit the shore, their radius of curvature is so large that they can be treated as plane waves. Hence they hit the shore nearly normal to the shore.
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Read the assertion and reason carefully to mark the correct option ou...
Assertion: Ocean waves hitting a beach are always found to be nearly normal to the shore.
Reason: Ocean waves are longitudinal waves.
Correct answer: Option 'C' - If the assertion is true but the reason is false.
Explanation:
The assertion states that ocean waves hitting a beach are always found to be nearly normal to the shore. This means that the direction of the waves is nearly perpendicular to the shoreline.
The reason given for this assertion is that ocean waves are longitudinal waves. However, this reason is incorrect. Ocean waves are actually transverse waves, not longitudinal waves.
Assertion explanation:
When ocean waves approach the shore, they experience a change in the depth of water. As the water becomes shallower near the shore, the bottom of the wave starts to slow down due to friction with the ocean floor, while the top of the wave continues moving at its original speed. This causes the wave to bend and the crest of the wave to become nearly perpendicular to the shoreline. This phenomenon is known as wave refraction.
Reason explanation:
Ocean waves are not longitudinal waves. Longitudinal waves are waves in which the particles of the medium vibrate parallel to the direction of wave propagation. Sound waves are examples of longitudinal waves.
Ocean waves, on the other hand, are transverse waves. Transverse waves are waves in which the particles of the medium vibrate perpendicular to the direction of wave propagation. In the case of ocean waves, the particles of water move up and down as the wave passes through, while the wave itself moves horizontally.
Therefore, the reason given in the statement is incorrect, as ocean waves are not longitudinal waves.
Conclusion:
Based on the above explanation, we can conclude that the assertion is true, as ocean waves hitting a beach are indeed nearly normal to the shore. However, the reason given for this assertion is false, as ocean waves are transverse waves, not longitudinal waves. Hence, the correct answer is option 'C'.
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