Consider the following statements regarding the generation of waves: 1. Waves lose energy and shrink as they move across the open ocean. 2. Most waves are caused by the wind driving against water. 3. Waves break when the water depth exceeds twice the wavelength. Which of the statements given above are correct?

The correct option is 2 only Explanation Ocean waves are oscillatory movements that result in the rise and fall of the water surface. They represent the transport of energy through the ocean, rather than the physical movement of the water mass itself over long distances. - Statement 1 is correct: The vast majority of ocean waves are generated by the friction between the wind and the surface water. As wind blows across the water, it transfers energy, creating ripples that eventually grow into larger waves. While other factors like seismic activity (tsunamis) can generate waves, wind is the predominant force. - Statement 2 is incorrect: Waves are highly efficient at transporting energy. Once formed, they can travel thousands of kilometers across the open ocean with minimal energy loss. They do not shrink significantly while moving through deep water; instead, they often organize into uniform patterns called swells. Significant energy loss occurs only when they encounter resistance, such as the seabed in shallow coastal areas. - Statement 3 is incorrect: Waves break when they enter shallow water, specifically when the water depth is less than half the wavelength. As the depth decreases, friction with the sea floor slows the bottom of the wave, causing the crest to steepen and eventually collapse. The condition "depth exceeds twice the wavelength" describes deep-water waves, which are stable and do not break. Key Takeaway: Wind is the primary source of wave energy. Waves sustain their energy over long distances in the open ocean and break only when the water depth becomes shallow relative to the wavelength, causing instability.

NCERT Class 11 Geography — Chapter 2: Movements of Ocean Water

mcqmedium

Consider the following statements regarding the generation of waves:

Waves lose energy and shrink as they move across the open ocean.
Most waves are caused by the wind driving against water.
Waves break when the water depth exceeds twice the wavelength.

Which of the statements given above are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1, 2 and 3
B1 and 3 only
C1 only
D2 only

Did you get this right?

Solution

The correct option is

2 only

Explanation

Ocean waves are oscillatory movements that result in the rise and fall of the water surface. They represent the transport of energy through the ocean, rather than the physical movement of the water mass itself over long distances.

Statement 1 is correct: The vast majority of ocean waves are generated by the friction between the wind and the surface water. As wind blows across the water, it transfers energy, creating ripples that eventually grow into larger waves. While other factors like seismic activity (tsunamis) can generate waves, wind is the predominant force.
Statement 2 is incorrect: Waves are highly efficient at transporting energy. Once formed, they can travel thousands of kilometers across the open ocean with minimal energy loss. They do not shrink significantly while moving through deep water; instead, they often organize into uniform patterns called swells. Significant energy loss occurs only when they encounter resistance, such as the seabed in shallow coastal areas.
Statement 3 is incorrect: Waves break when they enter shallow water, specifically when the water depth is less than half the wavelength. As the depth decreases, friction with the sea floor slows the bottom of the wave, causing the crest to steepen and eventually collapse. The condition "depth exceeds twice the wavelength" describes deep-water waves, which are stable and do not break.

Key Takeaway: Wind is the primary source of wave energy. Waves sustain their energy over long distances in the open ocean and break only when the water depth becomes shallow relative to the wavelength, causing instability.

Your note

More from Chapter 2: Movements of Ocean Water

Consider the following factors: 1. The shape of bays and estuaries has no influence on the magnitude of tides. 2. Presence of wide continental shelves. 3. Presence of mid-oceanic islands. Which of the above factors can influence the height or magnitude of tidal bulges?

medium

Which of the following best describes the general movement of warm ocean currents?

easy

With reference to the movements of ocean water, consider the following statements: 1. Ocean currents represent the horizontal motion of water while tides represent the vertical motion. 2. In waves, the water moves ahead from one place to another along with the wave train. 3. The upwelling of cold water from the subsurface is a form of horizontal motion. Which of the statements given above is/are correct?

medium

Consider the following statements regarding the characteristics of ocean waves: 1. The largest waves are typically found in open oceans rather than enclosed seas. 2. Steep waves are generally old and originate from far away places. 3. Slow and steady waves usually originate from far away places. Which of the statements given above is/are correct?

medium

The maximum height of a wave is determined by which of the following factors? 1. The strength of the wind has no role in determining wave height. 2. The duration for which the wind blows. 3. The area over which the wind blows in a single direction. Select the correct answer using the code given below:

easy

Keep practising Chapter 2: Movements of Ocean Water

Work through every question from this NCERT chapter.

Browse all NCERT Class 11 Geography chapters

The correct option is

2 only

Explanation

Statement 1 is correct: The vast majority of ocean waves are generated by the friction between the wind and the surface water. As wind blows across the water, it transfers energy, creating ripples that eventually grow into larger waves. While other factors like seismic activity (tsunamis) can generate waves, wind is the predominant force.
Statement 2 is incorrect: Waves are highly efficient at transporting energy. Once formed, they can travel thousands of kilometers across the open ocean with minimal energy loss. They do not shrink significantly while moving through deep water; instead, they often organize into uniform patterns called swells. Significant energy loss occurs only when they encounter resistance, such as the seabed in shallow coastal areas.
Statement 3 is incorrect: Waves break when they enter shallow water, specifically when the water depth is less than half the wavelength. As the depth decreases, friction with the sea floor slows the bottom of the wave, causing the crest to steepen and eventually collapse. The condition "depth exceeds twice the wavelength" describes deep-water waves, which are stable and do not break.