Class 11 Exam > Class 11 Questions > What is correct about wave number?a)It is def...
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What is correct about wave number?
- a)It is defined as the number of waves which pass through a particular point in one second
- b)It is defined as the number of wavelengths per unit length
- c)It is defined as the distance between two neighbouring crests or troughs of wave
- d)It is the distance travelled by a wave in one second
Correct answer is option 'B'. Can you explain this answer?
Most Upvoted Answer
What is correct about wave number?a)It is defined as the number of wav...
Wave number, a unit of frequency in atomic, molecular, and nuclear spectroscopy equal to the true frequency divided by the speed of light and thus equal to the number of waves in a unit distance. The frequency, symbolized by the Greek letter nu (ν), of any wave equals the speed of light, c, divided by the wavelength λ: thus ν = c/λ. A typical spectral line in the visible region of the spectrum has a wavelength of 5.8 X 10-5 cm; this wavelength corresponds to a frequency (ν) of 5.17 X1014 Hz (hertz equals one cycle per second) obtained from the equation. Because this frequency and others like it are so extremely large, it is convenient to divide the number by the speed of light and hence reduce its size. Frequency divided by the speed of light is ν/c, which from the above equation is 1/λ. When wavelength is measured in metres, 1/λ represents the number of waves of the wave train to be found in a length of one metre or, if measured in centimetres, the number in one centimetre. This number is called the wave number of the spectrum line. Wave numbers are usually measured in units of reciprocal metres (1/m, or m-1) and reciprocal centimetres (1/cm, or cm-1).
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What is correct about wave number?a)It is defined as the number of wav...
Wave Number:
Wave number is a term used in physics to describe the number of wavelengths per unit length. It is an important concept in the study of waves, particularly in the field of optics. The wave number is denoted by the symbol "k" and is typically expressed in units of radians per meter (rad/m).
Explanation:
The correct answer is option 'B' - "It is defined as the number of wavelengths per unit length". Here's why:
Definition:
Wave number is defined as the number of wavelengths that exist in one unit of length. It represents the spatial frequency of a wave, indicating how many wavelengths are present in a given distance.
Mathematical Expression:
Wave number (k) can be mathematically expressed as the ratio of 2π to the wavelength (λ) of the wave. This can be written as:
k = 2π/λ
Units:
Wave number is typically expressed in units of radians per meter (rad/m) or reciprocal meters (m⁻¹). This is because it represents the number of wavelengths per unit length.
Relation to Frequency and Speed:
Wave number is inversely proportional to wavelength. As wavelength increases, wave number decreases, and vice versa. It is also related to the frequency (f) and speed (v) of a wave through the wave equation:
v = fλ
Since frequency is the reciprocal of the period (T), the wave equation can also be written as:
v = (1/T)λ
Rearranging the equation, we get:
v = f(1/f) = f/f = 1/f
Substituting the value of wavelength (λ) from the wave number equation (k = 2π/λ), we have:
v = f/k
Applications:
Wave number is used in various branches of physics, such as optics, quantum mechanics, and electromagnetic theory. It is particularly useful in the analysis and description of periodic waves, including light waves, sound waves, and electromagnetic waves. In optics, wave number is used to describe the spatial variation of the electric and magnetic fields in a wave. It plays a significant role in phenomena like diffraction, interference, and polarization.
Therefore, the correct statement is option 'B' - "It is defined as the number of wavelengths per unit length".
Wave number is a term used in physics to describe the number of wavelengths per unit length. It is an important concept in the study of waves, particularly in the field of optics. The wave number is denoted by the symbol "k" and is typically expressed in units of radians per meter (rad/m).
Explanation:
The correct answer is option 'B' - "It is defined as the number of wavelengths per unit length". Here's why:
Definition:
Wave number is defined as the number of wavelengths that exist in one unit of length. It represents the spatial frequency of a wave, indicating how many wavelengths are present in a given distance.
Mathematical Expression:
Wave number (k) can be mathematically expressed as the ratio of 2π to the wavelength (λ) of the wave. This can be written as:
k = 2π/λ
Units:
Wave number is typically expressed in units of radians per meter (rad/m) or reciprocal meters (m⁻¹). This is because it represents the number of wavelengths per unit length.
Relation to Frequency and Speed:
Wave number is inversely proportional to wavelength. As wavelength increases, wave number decreases, and vice versa. It is also related to the frequency (f) and speed (v) of a wave through the wave equation:
v = fλ
Since frequency is the reciprocal of the period (T), the wave equation can also be written as:
v = (1/T)λ
Rearranging the equation, we get:
v = f(1/f) = f/f = 1/f
Substituting the value of wavelength (λ) from the wave number equation (k = 2π/λ), we have:
v = f/k
Applications:
Wave number is used in various branches of physics, such as optics, quantum mechanics, and electromagnetic theory. It is particularly useful in the analysis and description of periodic waves, including light waves, sound waves, and electromagnetic waves. In optics, wave number is used to describe the spatial variation of the electric and magnetic fields in a wave. It plays a significant role in phenomena like diffraction, interference, and polarization.
Therefore, the correct statement is option 'B' - "It is defined as the number of wavelengths per unit length".
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What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer? for Class 11 2025 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 11 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer?.
What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer? for Class 11 2025 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 11 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer?.
Solutions for What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 11.
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What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice What is correct about wave number?a)It is defined as the number of waves which pass through a particular point in one secondb)It is defined as the number of wavelengths per unit lengthc)It is defined as the distance between two neighbouring crests or troughs of waved)It is the distance travelled by a wave in one secondCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice Class 11 tests.
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