QBManager

Dual nature of radiation and Matter

142654 A laser beam has intensity $2.1 \times 10^{15} W / m^{2}$ . The amplitude of magnetic field in the beam in approximately is

1

1.4 T

2

4.2 T

3

1 T

4

1.5 T

Explanation:

B Given, Intensity as beam (I) $= 2.1 \times 10^{15} W / m^{2}$ We know that,
$I = \frac{1}{2} ε_{0} E_{o}^{2} c$
$E_{o}^{2} = \frac{2 I}{ε_{0} c}$
$E_{o} = \sqrt{\frac{2 I}{ε_{o} c}} = \sqrt{\frac{2 \times 2.1 \times 10^{15}}{8.85 \times 10^{- 12} \times 3 \times 10^{8}}}$
$E_{o} = 1.25775 \times 10^{9} N / C$
And
$B_{0} = μ_{0} ε_{0} {cE}_{0}$
$B_{0} = 4 π \times 10^{- 7} \times 8.85 \times 10^{- 12} \times 3 \times 10^{8} \times 1.25775 \times 10^{9}$
$B_{0} = 4.2 T$

Shift-II

Dual nature of radiation and Matter

142656 A 1 milliwatt laser source is emitting light of wavelength $555 nm$ . The number of photons emitted per second are approximately (Planck's constant $= 6.6 \times 10^{- 34} m^{2} Kg / s$ )

1

10^{7}

2

10^{11}

3

10^{15}

4

10^{18}

Explanation:

C Given that,
Energy of light $(P) = 1 mW = 1 \times 10^{- 3} W$
Wavelength $(λ) = 555 nm = 555 \times 10^{- 9} m$
Energy of 1 photon $(E) = \frac{h c}{λ}$
$E = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{555 \times 10^{- 9}}$
$E = 3.568 \times 10^{- 19}$
No. of photon $(N) = \frac{P}{E} = \frac{1 \times 10^{- 3}}{3.568 \times 10^{- 19}}$
$N = 2.8 \times 10^{15}$

UPSEE 2020

Dual nature of radiation and Matter

142657 The wavelength of helium-neon laser in air is $585 nm$ . As it enters the eye its wavelength changes to $450 nm$ . Calculate the velocity of the laser light inside the eyeball.

1

2.1 \times 10^{8} m / s

2

2.3 \times 10^{8} m / s

3

2.5 \times 10^{8} m / s

4

2.8 \times 10^{8} m / s

Explanation:

B Given that,
Wavelength of light in $air (λ_{1}) = 585 nm = 585 \times 10^{- 9} m$ Wavelength of light in eye $(λ_{2}) = 450 nm = 450 \times 10^{- 19} m$ We know that, velocity of laser in eye ball
$μ = \frac{c}{v} = v = \frac{c}{μ}$
And
$λ_{1} f = c$
$λ_{2} f = v$
From equation (i) \& (ii), when the light go from one medium to another medium only wavelength change frequency remains same.
$\frac{λ_{1} f}{λ_{2} f} = \frac{c}{v}$
$μ = \frac{λ_{1}}{λ_{2}} = \frac{585 \times 10^{- 9}}{450 \times 10^{- 9}} = 1.3$
Putting the value of $μ$ in equation (i)
$v = \frac{3 \times 10^{8}}{1.3}$
$v = 2.3 \times 10^{8} m / s$

AMU-2019

Dual nature of radiation and Matter

142658 Which of the following is not the property of laser beams?

1 Highly intense

2 Monochromatic

3 Directional

4 Incoherent

Explanation:

D following are the properties of laser beam -
$1.$ Coherence : Laser beam is highly coherent, meaning that the light waves are all in phase with each other resulting in a highly focused beam of light.
$2.$ Monochromatic : Laser beam is highly monochromatic, meaning that it consists of only one color or wavelength of light.
$3.$ Directionality :- Laser beam is highly directional, meaning that it can be focused into a very narrow beam that travels in a straight line.
$4.$ Intensity :- Laser beam is intense, meaning that it can be focused to produce a high amount of energy in a small area.
\(5. Polarization :- Laser beam is usually polarized. meaning that the electric field oscillates in a single plane.

UPSEE 2019

Dual nature of radiation and Matter

142659 A laser operating at a wavelength of $660 nm$ and the power 9 milli watt a target. How many number of photons arriving per second at the target? (Let h $= 6.6 \times 10^{- 34} J$ -s)

1

6 \times 10^{4}

2

6 \times 10^{16}

3

3 \times 10^{16}

4

5 \times 10^{14}

Explanation:

C Given, power(P) $= 9 mW = 9 \times 10^{- 3} W$
Wavelength $(λ) = 660 nm = 660 \times 10^{- 9} m$
We know that,
$Energy(E) = \frac{h c}{λ} = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{660 \times 10^{- 9}}$
$E = 0.03 \times 10^{- 17} J$
Number of photon emitted per second
$N = \frac{P}{E} = \frac{9 \times 10^{- 3}}{0.03 \times 10^{- 17}}$
$N = 3 \times 10^{16}$

Shift-I

Dual nature of radiation and Matter

142654 A laser beam has intensity $2.1 \times 10^{15} W / m^{2}$ . The amplitude of magnetic field in the beam in approximately is

1

1.4 T

2

4.2 T

3

1 T

4

1.5 T

Explanation:

B Given, Intensity as beam (I) $= 2.1 \times 10^{15} W / m^{2}$ We know that,
$I = \frac{1}{2} ε_{0} E_{o}^{2} c$
$E_{o}^{2} = \frac{2 I}{ε_{0} c}$
$E_{o} = \sqrt{\frac{2 I}{ε_{o} c}} = \sqrt{\frac{2 \times 2.1 \times 10^{15}}{8.85 \times 10^{- 12} \times 3 \times 10^{8}}}$
$E_{o} = 1.25775 \times 10^{9} N / C$
And
$B_{0} = μ_{0} ε_{0} {cE}_{0}$
$B_{0} = 4 π \times 10^{- 7} \times 8.85 \times 10^{- 12} \times 3 \times 10^{8} \times 1.25775 \times 10^{9}$
$B_{0} = 4.2 T$

Shift-II

Dual nature of radiation and Matter

142656 A 1 milliwatt laser source is emitting light of wavelength $555 nm$ . The number of photons emitted per second are approximately (Planck's constant $= 6.6 \times 10^{- 34} m^{2} Kg / s$ )

1

10^{7}

2

10^{11}

3

10^{15}

4

10^{18}

Explanation:

C Given that,
Energy of light $(P) = 1 mW = 1 \times 10^{- 3} W$
Wavelength $(λ) = 555 nm = 555 \times 10^{- 9} m$
Energy of 1 photon $(E) = \frac{h c}{λ}$
$E = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{555 \times 10^{- 9}}$
$E = 3.568 \times 10^{- 19}$
No. of photon $(N) = \frac{P}{E} = \frac{1 \times 10^{- 3}}{3.568 \times 10^{- 19}}$
$N = 2.8 \times 10^{15}$

UPSEE 2020

Dual nature of radiation and Matter

142657 The wavelength of helium-neon laser in air is $585 nm$ . As it enters the eye its wavelength changes to $450 nm$ . Calculate the velocity of the laser light inside the eyeball.

1

2.1 \times 10^{8} m / s

2

2.3 \times 10^{8} m / s

3

2.5 \times 10^{8} m / s

4

2.8 \times 10^{8} m / s

Explanation:

B Given that,
Wavelength of light in $air (λ_{1}) = 585 nm = 585 \times 10^{- 9} m$ Wavelength of light in eye $(λ_{2}) = 450 nm = 450 \times 10^{- 19} m$ We know that, velocity of laser in eye ball
$μ = \frac{c}{v} = v = \frac{c}{μ}$
And
$λ_{1} f = c$
$λ_{2} f = v$
From equation (i) \& (ii), when the light go from one medium to another medium only wavelength change frequency remains same.
$\frac{λ_{1} f}{λ_{2} f} = \frac{c}{v}$
$μ = \frac{λ_{1}}{λ_{2}} = \frac{585 \times 10^{- 9}}{450 \times 10^{- 9}} = 1.3$
Putting the value of $μ$ in equation (i)
$v = \frac{3 \times 10^{8}}{1.3}$
$v = 2.3 \times 10^{8} m / s$

AMU-2019

Dual nature of radiation and Matter

142658 Which of the following is not the property of laser beams?

1 Highly intense

2 Monochromatic

3 Directional

4 Incoherent

Explanation:

D following are the properties of laser beam -
$1.$ Coherence : Laser beam is highly coherent, meaning that the light waves are all in phase with each other resulting in a highly focused beam of light.
$2.$ Monochromatic : Laser beam is highly monochromatic, meaning that it consists of only one color or wavelength of light.
$3.$ Directionality :- Laser beam is highly directional, meaning that it can be focused into a very narrow beam that travels in a straight line.
$4.$ Intensity :- Laser beam is intense, meaning that it can be focused to produce a high amount of energy in a small area.
\(5. Polarization :- Laser beam is usually polarized. meaning that the electric field oscillates in a single plane.

UPSEE 2019

Dual nature of radiation and Matter

142659 A laser operating at a wavelength of $660 nm$ and the power 9 milli watt a target. How many number of photons arriving per second at the target? (Let h $= 6.6 \times 10^{- 34} J$ -s)

1

6 \times 10^{4}

2

6 \times 10^{16}

3

3 \times 10^{16}

4

5 \times 10^{14}

Explanation:

C Given, power(P) $= 9 mW = 9 \times 10^{- 3} W$
Wavelength $(λ) = 660 nm = 660 \times 10^{- 9} m$
We know that,
$Energy(E) = \frac{h c}{λ} = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{660 \times 10^{- 9}}$
$E = 0.03 \times 10^{- 17} J$
Number of photon emitted per second
$N = \frac{P}{E} = \frac{9 \times 10^{- 3}}{0.03 \times 10^{- 17}}$
$N = 3 \times 10^{16}$

Shift-I

Dual nature of radiation and Matter

142654 A laser beam has intensity $2.1 \times 10^{15} W / m^{2}$ . The amplitude of magnetic field in the beam in approximately is

1

1.4 T

2

4.2 T

3

1 T

4

1.5 T

Explanation:

B Given, Intensity as beam (I) $= 2.1 \times 10^{15} W / m^{2}$ We know that,
$I = \frac{1}{2} ε_{0} E_{o}^{2} c$
$E_{o}^{2} = \frac{2 I}{ε_{0} c}$
$E_{o} = \sqrt{\frac{2 I}{ε_{o} c}} = \sqrt{\frac{2 \times 2.1 \times 10^{15}}{8.85 \times 10^{- 12} \times 3 \times 10^{8}}}$
$E_{o} = 1.25775 \times 10^{9} N / C$
And
$B_{0} = μ_{0} ε_{0} {cE}_{0}$
$B_{0} = 4 π \times 10^{- 7} \times 8.85 \times 10^{- 12} \times 3 \times 10^{8} \times 1.25775 \times 10^{9}$
$B_{0} = 4.2 T$

Shift-II

Dual nature of radiation and Matter

142656 A 1 milliwatt laser source is emitting light of wavelength $555 nm$ . The number of photons emitted per second are approximately (Planck's constant $= 6.6 \times 10^{- 34} m^{2} Kg / s$ )

1

10^{7}

2

10^{11}

3

10^{15}

4

10^{18}

Explanation:

C Given that,
Energy of light $(P) = 1 mW = 1 \times 10^{- 3} W$
Wavelength $(λ) = 555 nm = 555 \times 10^{- 9} m$
Energy of 1 photon $(E) = \frac{h c}{λ}$
$E = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{555 \times 10^{- 9}}$
$E = 3.568 \times 10^{- 19}$
No. of photon $(N) = \frac{P}{E} = \frac{1 \times 10^{- 3}}{3.568 \times 10^{- 19}}$
$N = 2.8 \times 10^{15}$

UPSEE 2020

Dual nature of radiation and Matter

142657 The wavelength of helium-neon laser in air is $585 nm$ . As it enters the eye its wavelength changes to $450 nm$ . Calculate the velocity of the laser light inside the eyeball.

1

2.1 \times 10^{8} m / s

2

2.3 \times 10^{8} m / s

3

2.5 \times 10^{8} m / s

4

2.8 \times 10^{8} m / s

Explanation:

B Given that,
Wavelength of light in $air (λ_{1}) = 585 nm = 585 \times 10^{- 9} m$ Wavelength of light in eye $(λ_{2}) = 450 nm = 450 \times 10^{- 19} m$ We know that, velocity of laser in eye ball
$μ = \frac{c}{v} = v = \frac{c}{μ}$
And
$λ_{1} f = c$
$λ_{2} f = v$
From equation (i) \& (ii), when the light go from one medium to another medium only wavelength change frequency remains same.
$\frac{λ_{1} f}{λ_{2} f} = \frac{c}{v}$
$μ = \frac{λ_{1}}{λ_{2}} = \frac{585 \times 10^{- 9}}{450 \times 10^{- 9}} = 1.3$
Putting the value of $μ$ in equation (i)
$v = \frac{3 \times 10^{8}}{1.3}$
$v = 2.3 \times 10^{8} m / s$

AMU-2019

Dual nature of radiation and Matter

142658 Which of the following is not the property of laser beams?

1 Highly intense

2 Monochromatic

3 Directional

4 Incoherent

Explanation:

D following are the properties of laser beam -
$1.$ Coherence : Laser beam is highly coherent, meaning that the light waves are all in phase with each other resulting in a highly focused beam of light.
$2.$ Monochromatic : Laser beam is highly monochromatic, meaning that it consists of only one color or wavelength of light.
$3.$ Directionality :- Laser beam is highly directional, meaning that it can be focused into a very narrow beam that travels in a straight line.
$4.$ Intensity :- Laser beam is intense, meaning that it can be focused to produce a high amount of energy in a small area.
\(5. Polarization :- Laser beam is usually polarized. meaning that the electric field oscillates in a single plane.

UPSEE 2019

Dual nature of radiation and Matter

142659 A laser operating at a wavelength of $660 nm$ and the power 9 milli watt a target. How many number of photons arriving per second at the target? (Let h $= 6.6 \times 10^{- 34} J$ -s)

1

6 \times 10^{4}

2

6 \times 10^{16}

3

3 \times 10^{16}

4

5 \times 10^{14}

Explanation:

C Given, power(P) $= 9 mW = 9 \times 10^{- 3} W$
Wavelength $(λ) = 660 nm = 660 \times 10^{- 9} m$
We know that,
$Energy(E) = \frac{h c}{λ} = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{660 \times 10^{- 9}}$
$E = 0.03 \times 10^{- 17} J$
Number of photon emitted per second
$N = \frac{P}{E} = \frac{9 \times 10^{- 3}}{0.03 \times 10^{- 17}}$
$N = 3 \times 10^{16}$

Shift-I

Dual nature of radiation and Matter

142654 A laser beam has intensity $2.1 \times 10^{15} W / m^{2}$ . The amplitude of magnetic field in the beam in approximately is

1

1.4 T

2

4.2 T

3

1 T

4

1.5 T

Explanation:

B Given, Intensity as beam (I) $= 2.1 \times 10^{15} W / m^{2}$ We know that,
$I = \frac{1}{2} ε_{0} E_{o}^{2} c$
$E_{o}^{2} = \frac{2 I}{ε_{0} c}$
$E_{o} = \sqrt{\frac{2 I}{ε_{o} c}} = \sqrt{\frac{2 \times 2.1 \times 10^{15}}{8.85 \times 10^{- 12} \times 3 \times 10^{8}}}$
$E_{o} = 1.25775 \times 10^{9} N / C$
And
$B_{0} = μ_{0} ε_{0} {cE}_{0}$
$B_{0} = 4 π \times 10^{- 7} \times 8.85 \times 10^{- 12} \times 3 \times 10^{8} \times 1.25775 \times 10^{9}$
$B_{0} = 4.2 T$

Shift-II

Dual nature of radiation and Matter

142656 A 1 milliwatt laser source is emitting light of wavelength $555 nm$ . The number of photons emitted per second are approximately (Planck's constant $= 6.6 \times 10^{- 34} m^{2} Kg / s$ )

1

10^{7}

2

10^{11}

3

10^{15}

4

10^{18}

Explanation:

C Given that,
Energy of light $(P) = 1 mW = 1 \times 10^{- 3} W$
Wavelength $(λ) = 555 nm = 555 \times 10^{- 9} m$
Energy of 1 photon $(E) = \frac{h c}{λ}$
$E = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{555 \times 10^{- 9}}$
$E = 3.568 \times 10^{- 19}$
No. of photon $(N) = \frac{P}{E} = \frac{1 \times 10^{- 3}}{3.568 \times 10^{- 19}}$
$N = 2.8 \times 10^{15}$

UPSEE 2020

Dual nature of radiation and Matter

142657 The wavelength of helium-neon laser in air is $585 nm$ . As it enters the eye its wavelength changes to $450 nm$ . Calculate the velocity of the laser light inside the eyeball.

1

2.1 \times 10^{8} m / s

2

2.3 \times 10^{8} m / s

3

2.5 \times 10^{8} m / s

4

2.8 \times 10^{8} m / s

Explanation:

B Given that,
Wavelength of light in $air (λ_{1}) = 585 nm = 585 \times 10^{- 9} m$ Wavelength of light in eye $(λ_{2}) = 450 nm = 450 \times 10^{- 19} m$ We know that, velocity of laser in eye ball
$μ = \frac{c}{v} = v = \frac{c}{μ}$
And
$λ_{1} f = c$
$λ_{2} f = v$
From equation (i) \& (ii), when the light go from one medium to another medium only wavelength change frequency remains same.
$\frac{λ_{1} f}{λ_{2} f} = \frac{c}{v}$
$μ = \frac{λ_{1}}{λ_{2}} = \frac{585 \times 10^{- 9}}{450 \times 10^{- 9}} = 1.3$
Putting the value of $μ$ in equation (i)
$v = \frac{3 \times 10^{8}}{1.3}$
$v = 2.3 \times 10^{8} m / s$

AMU-2019

Dual nature of radiation and Matter

142658 Which of the following is not the property of laser beams?

1 Highly intense

2 Monochromatic

3 Directional

4 Incoherent

Explanation:

D following are the properties of laser beam -
$1.$ Coherence : Laser beam is highly coherent, meaning that the light waves are all in phase with each other resulting in a highly focused beam of light.
$2.$ Monochromatic : Laser beam is highly monochromatic, meaning that it consists of only one color or wavelength of light.
$3.$ Directionality :- Laser beam is highly directional, meaning that it can be focused into a very narrow beam that travels in a straight line.
$4.$ Intensity :- Laser beam is intense, meaning that it can be focused to produce a high amount of energy in a small area.
\(5. Polarization :- Laser beam is usually polarized. meaning that the electric field oscillates in a single plane.

UPSEE 2019

Dual nature of radiation and Matter

142659 A laser operating at a wavelength of $660 nm$ and the power 9 milli watt a target. How many number of photons arriving per second at the target? (Let h $= 6.6 \times 10^{- 34} J$ -s)

1

6 \times 10^{4}

2

6 \times 10^{16}

3

3 \times 10^{16}

4

5 \times 10^{14}

Explanation:

C Given, power(P) $= 9 mW = 9 \times 10^{- 3} W$
Wavelength $(λ) = 660 nm = 660 \times 10^{- 9} m$
We know that,
$Energy(E) = \frac{h c}{λ} = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{660 \times 10^{- 9}}$
$E = 0.03 \times 10^{- 17} J$
Number of photon emitted per second
$N = \frac{P}{E} = \frac{9 \times 10^{- 3}}{0.03 \times 10^{- 17}}$
$N = 3 \times 10^{16}$

Shift-I

Dual nature of radiation and Matter

142654 A laser beam has intensity $2.1 \times 10^{15} W / m^{2}$ . The amplitude of magnetic field in the beam in approximately is

1

1.4 T

2

4.2 T

3

1 T

4

1.5 T

Explanation:

B Given, Intensity as beam (I) $= 2.1 \times 10^{15} W / m^{2}$ We know that,
$I = \frac{1}{2} ε_{0} E_{o}^{2} c$
$E_{o}^{2} = \frac{2 I}{ε_{0} c}$
$E_{o} = \sqrt{\frac{2 I}{ε_{o} c}} = \sqrt{\frac{2 \times 2.1 \times 10^{15}}{8.85 \times 10^{- 12} \times 3 \times 10^{8}}}$
$E_{o} = 1.25775 \times 10^{9} N / C$
And
$B_{0} = μ_{0} ε_{0} {cE}_{0}$
$B_{0} = 4 π \times 10^{- 7} \times 8.85 \times 10^{- 12} \times 3 \times 10^{8} \times 1.25775 \times 10^{9}$
$B_{0} = 4.2 T$

Shift-II

Dual nature of radiation and Matter

142656 A 1 milliwatt laser source is emitting light of wavelength $555 nm$ . The number of photons emitted per second are approximately (Planck's constant $= 6.6 \times 10^{- 34} m^{2} Kg / s$ )

1

10^{7}

2

10^{11}

3

10^{15}

4

10^{18}

Explanation:

C Given that,
Energy of light $(P) = 1 mW = 1 \times 10^{- 3} W$
Wavelength $(λ) = 555 nm = 555 \times 10^{- 9} m$
Energy of 1 photon $(E) = \frac{h c}{λ}$
$E = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{555 \times 10^{- 9}}$
$E = 3.568 \times 10^{- 19}$
No. of photon $(N) = \frac{P}{E} = \frac{1 \times 10^{- 3}}{3.568 \times 10^{- 19}}$
$N = 2.8 \times 10^{15}$

UPSEE 2020

Dual nature of radiation and Matter

142657 The wavelength of helium-neon laser in air is $585 nm$ . As it enters the eye its wavelength changes to $450 nm$ . Calculate the velocity of the laser light inside the eyeball.

1

2.1 \times 10^{8} m / s

2

2.3 \times 10^{8} m / s

3

2.5 \times 10^{8} m / s

4

2.8 \times 10^{8} m / s

Explanation:

B Given that,
Wavelength of light in $air (λ_{1}) = 585 nm = 585 \times 10^{- 9} m$ Wavelength of light in eye $(λ_{2}) = 450 nm = 450 \times 10^{- 19} m$ We know that, velocity of laser in eye ball
$μ = \frac{c}{v} = v = \frac{c}{μ}$
And
$λ_{1} f = c$
$λ_{2} f = v$
From equation (i) \& (ii), when the light go from one medium to another medium only wavelength change frequency remains same.
$\frac{λ_{1} f}{λ_{2} f} = \frac{c}{v}$
$μ = \frac{λ_{1}}{λ_{2}} = \frac{585 \times 10^{- 9}}{450 \times 10^{- 9}} = 1.3$
Putting the value of $μ$ in equation (i)
$v = \frac{3 \times 10^{8}}{1.3}$
$v = 2.3 \times 10^{8} m / s$

AMU-2019

Dual nature of radiation and Matter

142658 Which of the following is not the property of laser beams?

1 Highly intense

2 Monochromatic

3 Directional

4 Incoherent

Explanation:

D following are the properties of laser beam -
$1.$ Coherence : Laser beam is highly coherent, meaning that the light waves are all in phase with each other resulting in a highly focused beam of light.
$2.$ Monochromatic : Laser beam is highly monochromatic, meaning that it consists of only one color or wavelength of light.
$3.$ Directionality :- Laser beam is highly directional, meaning that it can be focused into a very narrow beam that travels in a straight line.
$4.$ Intensity :- Laser beam is intense, meaning that it can be focused to produce a high amount of energy in a small area.
\(5. Polarization :- Laser beam is usually polarized. meaning that the electric field oscillates in a single plane.

UPSEE 2019

Dual nature of radiation and Matter

142659 A laser operating at a wavelength of $660 nm$ and the power 9 milli watt a target. How many number of photons arriving per second at the target? (Let h $= 6.6 \times 10^{- 34} J$ -s)

1

6 \times 10^{4}

2

6 \times 10^{16}

3

3 \times 10^{16}

4

5 \times 10^{14}

Explanation:

C Given, power(P) $= 9 mW = 9 \times 10^{- 3} W$
Wavelength $(λ) = 660 nm = 660 \times 10^{- 9} m$
We know that,
$Energy(E) = \frac{h c}{λ} = \frac{6.6 \times 10^{- 34} \times 3 \times 10^{8}}{660 \times 10^{- 9}}$
$E = 0.03 \times 10^{- 17} J$
Number of photon emitted per second
$N = \frac{P}{E} = \frac{9 \times 10^{- 3}}{0.03 \times 10^{- 17}}$
$N = 3 \times 10^{16}$

Shift-I