Answer
438k+ views
Hint:The intensity, in general, refers to the measurement of energy flux over an area. Hence, it measures the amount of energy travelling through a certain region during a certain period of time. Hence, the S.I unit will be \[W{{m}^{-2}}\].
Complete step by step solution:
The intensity usually is a measure of the energy flux flowing or passing through an area over a period of time. In the photon picture, a light wave consists of multiple photons. Each of these photons is considered to be energy packets carrying a certain amount of energy.
The energy of a photon is given by: \[E=hv\], where (E) is the energy of the photon, (h) is the Planck’s constant, and ($v$) is the frequency of the photon.
The Standard unit of energy is Joule.
A light wave contains multiple energy packets of photons. Hence the energy of a light wave is given by: \[E=nhv\], where (n) is any natural number.
Further, as per the definition of Intensity, the amount of energy flux passing over an area over a period of time is the Intensity. Hence, let’s consider a surface area of $1{{m}^{2}}$and the amount of flux passing through it is; \[E=nhv\]. Let the amount of time in which the light wave hits the surface area be 1 second.
Hence, the Intensity becomes: $I=\dfrac{E\ J}{(Area\ {{m}^{2}})(Time\ s)}=\dfrac{nhv\ J}{(1\ {{m}^{2}})(1\ s)}$. The Intensity’s unit hence becomes:$I=\dfrac{J}{s}\dfrac{1}{{{m}^{2}}}$and we know that$\dfrac{J}{s}=W$, where W is the unit Wattage signifying energy per unit time.
Therefore, the S.I unit of Intensity becomes: $I=\dfrac{W}{{{m}^{2}}}$, since all the S.I units have been used for the relations.
Note:
The energy of a single photon given by: \[E=hv\], is the smallest amount of energy possible also known as a quanta.
A monochromatic light wave consists of photons, all of which are of the same frequency.
Complete step by step solution:
The intensity usually is a measure of the energy flux flowing or passing through an area over a period of time. In the photon picture, a light wave consists of multiple photons. Each of these photons is considered to be energy packets carrying a certain amount of energy.
The energy of a photon is given by: \[E=hv\], where (E) is the energy of the photon, (h) is the Planck’s constant, and ($v$) is the frequency of the photon.
The Standard unit of energy is Joule.
A light wave contains multiple energy packets of photons. Hence the energy of a light wave is given by: \[E=nhv\], where (n) is any natural number.
Further, as per the definition of Intensity, the amount of energy flux passing over an area over a period of time is the Intensity. Hence, let’s consider a surface area of $1{{m}^{2}}$and the amount of flux passing through it is; \[E=nhv\]. Let the amount of time in which the light wave hits the surface area be 1 second.
Hence, the Intensity becomes: $I=\dfrac{E\ J}{(Area\ {{m}^{2}})(Time\ s)}=\dfrac{nhv\ J}{(1\ {{m}^{2}})(1\ s)}$. The Intensity’s unit hence becomes:$I=\dfrac{J}{s}\dfrac{1}{{{m}^{2}}}$and we know that$\dfrac{J}{s}=W$, where W is the unit Wattage signifying energy per unit time.
Therefore, the S.I unit of Intensity becomes: $I=\dfrac{W}{{{m}^{2}}}$, since all the S.I units have been used for the relations.
Note:
The energy of a single photon given by: \[E=hv\], is the smallest amount of energy possible also known as a quanta.
A monochromatic light wave consists of photons, all of which are of the same frequency.
Recently Updated Pages
What are the figures of speech in the poem Wind class 11 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Write down 5 differences between Ntype and Ptype s class 11 physics CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Two tankers contain 850 litres and 680 litres of petrol class 10 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
What happens when eggshell is added to nitric acid class 12 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Why was Kamaraj called as Kingmaker class 10 social studies CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
What makes elections in India democratic class 11 social science CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Trending doubts
Which are the Top 10 Largest Countries of the World?
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Differentiate between orbit and orbital class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
What do you understand about stationary states class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Differentiate between homogeneous and heterogeneous class 12 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Write the difference between order and molecularity class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Common indicator organism of water pollution is A Escherichia class 12 biology CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths
![arrow-right](/cdn/images/seo-templates/arrow-right.png)