357833
In a \(p - n\) junction photocell, the value of the photo-electromotive force produced by monochromatic light is proportional to
1 the barrier voltage at the \(p - n\) junction
2 this intensity of the light falling on the cell
3 the frequency of the light falling on the cell
4 the voltage applied at the \(p - n\) junction
Explanation:
In a photoconductive cell, when monochromatic light is incident on the transparent metallic film, a force produced called the photoelectromotive, stimulates the emission of an electric current when photovoltaic action creates a potential difference between two points.The magnitude of this current depends upon the intensity of incident light. Hence, photo-electromotive force produced by monochromatic light is proportional to the intensity of the light falling on the cell.
PHXII11:DUAL NATURE OF RADIATION AND MATTER
357834
If \(5 \%\) of the energy supplied to a bulb is irradiated as visible light, how many quanta are emitted per second by a \(100{\rm{ }}W\) lamp? (Assume, wavelength of visible light as \({5.6 \times {{10}^{ - 5}}\;cm}\))
1 \(1.4 \times 10^{19}\)
2 \(3 \times 10^{3}\)
3 \(1.4 \times 10^{-19}\)
4 \(3 \times 10^{4}\)
Explanation:
Energy radiated as visible light \( = \frac{5}{{100}} \times 100 = 5\,J{s^{ - 1}}\) Let \(n\) be the number of photons emitted per second. Then, \(n h v=E=5\) \(\therefore n = \frac{{5\lambda }}{{hc}} = \frac{{5 \times 5.6 \times {{10}^{ - 7}}}}{{\left( {6.62 \times {{10}^{ - 34}}\left( {3 \times {{10}^8}} \right)} \right)}}\) \(\left[ {\because E = \frac{{hc}}{\lambda }} \right]\) \(\Rightarrow n=1.4 \times 10^{19}\)
AIIMS - 2011
PHXII11:DUAL NATURE OF RADIATION AND MATTER
357835
A photon of wavelength 6630 \( \mathop A^{~~\circ} \) is incident on a totally reflecting surface. The momentum delivered by the photon is equal to
1 \({6.63 \times 10^{-27} {~kg} {~m} / {s}}\)
2 \({2 \times 10^{-27} {~kg} {~m} / {s}}\)
3 \({3.33 \times 10^{-27} {~kg} {~m} / {s}}\)
4 \({10^{-27} {~kg} {~m} / {s}}\)
Explanation:
Momentum of the photon is \({\Rightarrow p=\dfrac{h}{\lambda}}\) Here \({h=}\) Planck's constant Momentum delivered by the photon \({=2 p=\dfrac{2 \times 6.63 \times 10^{-34}}{6630 \times 10^{-10}}=2 \times 10^{-27} {~kg} {~m} / {s}}\). So correct option is (2)
357833
In a \(p - n\) junction photocell, the value of the photo-electromotive force produced by monochromatic light is proportional to
1 the barrier voltage at the \(p - n\) junction
2 this intensity of the light falling on the cell
3 the frequency of the light falling on the cell
4 the voltage applied at the \(p - n\) junction
Explanation:
In a photoconductive cell, when monochromatic light is incident on the transparent metallic film, a force produced called the photoelectromotive, stimulates the emission of an electric current when photovoltaic action creates a potential difference between two points.The magnitude of this current depends upon the intensity of incident light. Hence, photo-electromotive force produced by monochromatic light is proportional to the intensity of the light falling on the cell.
PHXII11:DUAL NATURE OF RADIATION AND MATTER
357834
If \(5 \%\) of the energy supplied to a bulb is irradiated as visible light, how many quanta are emitted per second by a \(100{\rm{ }}W\) lamp? (Assume, wavelength of visible light as \({5.6 \times {{10}^{ - 5}}\;cm}\))
1 \(1.4 \times 10^{19}\)
2 \(3 \times 10^{3}\)
3 \(1.4 \times 10^{-19}\)
4 \(3 \times 10^{4}\)
Explanation:
Energy radiated as visible light \( = \frac{5}{{100}} \times 100 = 5\,J{s^{ - 1}}\) Let \(n\) be the number of photons emitted per second. Then, \(n h v=E=5\) \(\therefore n = \frac{{5\lambda }}{{hc}} = \frac{{5 \times 5.6 \times {{10}^{ - 7}}}}{{\left( {6.62 \times {{10}^{ - 34}}\left( {3 \times {{10}^8}} \right)} \right)}}\) \(\left[ {\because E = \frac{{hc}}{\lambda }} \right]\) \(\Rightarrow n=1.4 \times 10^{19}\)
AIIMS - 2011
PHXII11:DUAL NATURE OF RADIATION AND MATTER
357835
A photon of wavelength 6630 \( \mathop A^{~~\circ} \) is incident on a totally reflecting surface. The momentum delivered by the photon is equal to
1 \({6.63 \times 10^{-27} {~kg} {~m} / {s}}\)
2 \({2 \times 10^{-27} {~kg} {~m} / {s}}\)
3 \({3.33 \times 10^{-27} {~kg} {~m} / {s}}\)
4 \({10^{-27} {~kg} {~m} / {s}}\)
Explanation:
Momentum of the photon is \({\Rightarrow p=\dfrac{h}{\lambda}}\) Here \({h=}\) Planck's constant Momentum delivered by the photon \({=2 p=\dfrac{2 \times 6.63 \times 10^{-34}}{6630 \times 10^{-10}}=2 \times 10^{-27} {~kg} {~m} / {s}}\). So correct option is (2)
357833
In a \(p - n\) junction photocell, the value of the photo-electromotive force produced by monochromatic light is proportional to
1 the barrier voltage at the \(p - n\) junction
2 this intensity of the light falling on the cell
3 the frequency of the light falling on the cell
4 the voltage applied at the \(p - n\) junction
Explanation:
In a photoconductive cell, when monochromatic light is incident on the transparent metallic film, a force produced called the photoelectromotive, stimulates the emission of an electric current when photovoltaic action creates a potential difference between two points.The magnitude of this current depends upon the intensity of incident light. Hence, photo-electromotive force produced by monochromatic light is proportional to the intensity of the light falling on the cell.
PHXII11:DUAL NATURE OF RADIATION AND MATTER
357834
If \(5 \%\) of the energy supplied to a bulb is irradiated as visible light, how many quanta are emitted per second by a \(100{\rm{ }}W\) lamp? (Assume, wavelength of visible light as \({5.6 \times {{10}^{ - 5}}\;cm}\))
1 \(1.4 \times 10^{19}\)
2 \(3 \times 10^{3}\)
3 \(1.4 \times 10^{-19}\)
4 \(3 \times 10^{4}\)
Explanation:
Energy radiated as visible light \( = \frac{5}{{100}} \times 100 = 5\,J{s^{ - 1}}\) Let \(n\) be the number of photons emitted per second. Then, \(n h v=E=5\) \(\therefore n = \frac{{5\lambda }}{{hc}} = \frac{{5 \times 5.6 \times {{10}^{ - 7}}}}{{\left( {6.62 \times {{10}^{ - 34}}\left( {3 \times {{10}^8}} \right)} \right)}}\) \(\left[ {\because E = \frac{{hc}}{\lambda }} \right]\) \(\Rightarrow n=1.4 \times 10^{19}\)
AIIMS - 2011
PHXII11:DUAL NATURE OF RADIATION AND MATTER
357835
A photon of wavelength 6630 \( \mathop A^{~~\circ} \) is incident on a totally reflecting surface. The momentum delivered by the photon is equal to
1 \({6.63 \times 10^{-27} {~kg} {~m} / {s}}\)
2 \({2 \times 10^{-27} {~kg} {~m} / {s}}\)
3 \({3.33 \times 10^{-27} {~kg} {~m} / {s}}\)
4 \({10^{-27} {~kg} {~m} / {s}}\)
Explanation:
Momentum of the photon is \({\Rightarrow p=\dfrac{h}{\lambda}}\) Here \({h=}\) Planck's constant Momentum delivered by the photon \({=2 p=\dfrac{2 \times 6.63 \times 10^{-34}}{6630 \times 10^{-10}}=2 \times 10^{-27} {~kg} {~m} / {s}}\). So correct option is (2)
