Electron Emission, Photo Electric Effect (Threshol Frequency Stopping Potential)
Dual nature of radiation and Matter

142038 In a photoelectric experiment, a monochromatic light is incident on the emitter plate $E$, as shown in the figure. When switch $S_{1}$ is closed and switch $S_{2}$ is open, the photoelectrons strike the collector plate $\mathrm{C}$ with a maximum kinetic energy of $1 \mathrm{eV}$. If switch $S_{1}$ is open and switch $S_{2}$ is closed and the frequency of the incident light is doubled the photoelectrons strike the collector plate with a maximum kinetic energy of $20 \mathrm{eV}$. The threshold wavelength of the emitter plate.

1 $5233.3 \AA$
2 $4133.3 \AA$
3 $4166.7 \AA$
4 $5336.7 \AA$
Dual nature of radiation and Matter

142035 Assertion: Photoelectric effect demonstrates the wave nature of light.
Reason: The number of photoelectrons is proportional to the frequency of light.

1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
5 If the Assertion is incorrect but the Reason is correct.
Dual nature of radiation and Matter

142040 A cobalt $(\mathrm{Co})$ plate is placed at a distance of 1 $m$ from a point source of power $1 \mathrm{~W}$. Assume a circular area of the plate of radius, $r=1 \mathrm{~A}$ is exposed to the radiation and ejects photo electrons. The light energy is considered to be spread uniformly and the work function of cobalt is $5 \mathrm{eV}$. The minimum time the target should be exposed to the light source to eject a photoelectron (Assuming no reflection losses) is

1 $320 \mathrm{~s}$
2 $450 \mathrm{~s}$
3 $860 \mathrm{~s}$
4 $100 \mathrm{~s}$
Dual nature of radiation and Matter

142041 A photodiode sensor is used to measure the output of a $300 \mathrm{~W}$ lamp kept $10 \mathrm{~m}$ away. The sensor has an opening of $2 \mathrm{~cm}$ in diameter. How many photons enter the sensor if the wavelength of the light is $660 \mathrm{~nm}$ and the exposure time is $100 \mathrm{~ms}$. (Assume that all the energy of the lamp is given off as light and $h=$ $6.6 \times 10^{-34} \mathrm{Js}$ )

1 $3.6 \times 10^{13}$
2 $2.8 \times 10^{13}$
3 $2.5 \times 10^{13}$
4 $1.8 \times 10^{13}$
Dual nature of radiation and Matter

142038 In a photoelectric experiment, a monochromatic light is incident on the emitter plate $E$, as shown in the figure. When switch $S_{1}$ is closed and switch $S_{2}$ is open, the photoelectrons strike the collector plate $\mathrm{C}$ with a maximum kinetic energy of $1 \mathrm{eV}$. If switch $S_{1}$ is open and switch $S_{2}$ is closed and the frequency of the incident light is doubled the photoelectrons strike the collector plate with a maximum kinetic energy of $20 \mathrm{eV}$. The threshold wavelength of the emitter plate.

1 $5233.3 \AA$
2 $4133.3 \AA$
3 $4166.7 \AA$
4 $5336.7 \AA$
Dual nature of radiation and Matter

142035 Assertion: Photoelectric effect demonstrates the wave nature of light.
Reason: The number of photoelectrons is proportional to the frequency of light.

1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
5 If the Assertion is incorrect but the Reason is correct.
Dual nature of radiation and Matter

142040 A cobalt $(\mathrm{Co})$ plate is placed at a distance of 1 $m$ from a point source of power $1 \mathrm{~W}$. Assume a circular area of the plate of radius, $r=1 \mathrm{~A}$ is exposed to the radiation and ejects photo electrons. The light energy is considered to be spread uniformly and the work function of cobalt is $5 \mathrm{eV}$. The minimum time the target should be exposed to the light source to eject a photoelectron (Assuming no reflection losses) is

1 $320 \mathrm{~s}$
2 $450 \mathrm{~s}$
3 $860 \mathrm{~s}$
4 $100 \mathrm{~s}$
Dual nature of radiation and Matter

142041 A photodiode sensor is used to measure the output of a $300 \mathrm{~W}$ lamp kept $10 \mathrm{~m}$ away. The sensor has an opening of $2 \mathrm{~cm}$ in diameter. How many photons enter the sensor if the wavelength of the light is $660 \mathrm{~nm}$ and the exposure time is $100 \mathrm{~ms}$. (Assume that all the energy of the lamp is given off as light and $h=$ $6.6 \times 10^{-34} \mathrm{Js}$ )

1 $3.6 \times 10^{13}$
2 $2.8 \times 10^{13}$
3 $2.5 \times 10^{13}$
4 $1.8 \times 10^{13}$
Dual nature of radiation and Matter

142038 In a photoelectric experiment, a monochromatic light is incident on the emitter plate $E$, as shown in the figure. When switch $S_{1}$ is closed and switch $S_{2}$ is open, the photoelectrons strike the collector plate $\mathrm{C}$ with a maximum kinetic energy of $1 \mathrm{eV}$. If switch $S_{1}$ is open and switch $S_{2}$ is closed and the frequency of the incident light is doubled the photoelectrons strike the collector plate with a maximum kinetic energy of $20 \mathrm{eV}$. The threshold wavelength of the emitter plate.

1 $5233.3 \AA$
2 $4133.3 \AA$
3 $4166.7 \AA$
4 $5336.7 \AA$
Dual nature of radiation and Matter

142035 Assertion: Photoelectric effect demonstrates the wave nature of light.
Reason: The number of photoelectrons is proportional to the frequency of light.

1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
5 If the Assertion is incorrect but the Reason is correct.
Dual nature of radiation and Matter

142040 A cobalt $(\mathrm{Co})$ plate is placed at a distance of 1 $m$ from a point source of power $1 \mathrm{~W}$. Assume a circular area of the plate of radius, $r=1 \mathrm{~A}$ is exposed to the radiation and ejects photo electrons. The light energy is considered to be spread uniformly and the work function of cobalt is $5 \mathrm{eV}$. The minimum time the target should be exposed to the light source to eject a photoelectron (Assuming no reflection losses) is

1 $320 \mathrm{~s}$
2 $450 \mathrm{~s}$
3 $860 \mathrm{~s}$
4 $100 \mathrm{~s}$
Dual nature of radiation and Matter

142041 A photodiode sensor is used to measure the output of a $300 \mathrm{~W}$ lamp kept $10 \mathrm{~m}$ away. The sensor has an opening of $2 \mathrm{~cm}$ in diameter. How many photons enter the sensor if the wavelength of the light is $660 \mathrm{~nm}$ and the exposure time is $100 \mathrm{~ms}$. (Assume that all the energy of the lamp is given off as light and $h=$ $6.6 \times 10^{-34} \mathrm{Js}$ )

1 $3.6 \times 10^{13}$
2 $2.8 \times 10^{13}$
3 $2.5 \times 10^{13}$
4 $1.8 \times 10^{13}$
Dual nature of radiation and Matter

142038 In a photoelectric experiment, a monochromatic light is incident on the emitter plate $E$, as shown in the figure. When switch $S_{1}$ is closed and switch $S_{2}$ is open, the photoelectrons strike the collector plate $\mathrm{C}$ with a maximum kinetic energy of $1 \mathrm{eV}$. If switch $S_{1}$ is open and switch $S_{2}$ is closed and the frequency of the incident light is doubled the photoelectrons strike the collector plate with a maximum kinetic energy of $20 \mathrm{eV}$. The threshold wavelength of the emitter plate.

1 $5233.3 \AA$
2 $4133.3 \AA$
3 $4166.7 \AA$
4 $5336.7 \AA$
Dual nature of radiation and Matter

142035 Assertion: Photoelectric effect demonstrates the wave nature of light.
Reason: The number of photoelectrons is proportional to the frequency of light.

1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
5 If the Assertion is incorrect but the Reason is correct.
Dual nature of radiation and Matter

142040 A cobalt $(\mathrm{Co})$ plate is placed at a distance of 1 $m$ from a point source of power $1 \mathrm{~W}$. Assume a circular area of the plate of radius, $r=1 \mathrm{~A}$ is exposed to the radiation and ejects photo electrons. The light energy is considered to be spread uniformly and the work function of cobalt is $5 \mathrm{eV}$. The minimum time the target should be exposed to the light source to eject a photoelectron (Assuming no reflection losses) is

1 $320 \mathrm{~s}$
2 $450 \mathrm{~s}$
3 $860 \mathrm{~s}$
4 $100 \mathrm{~s}$
Dual nature of radiation and Matter

142041 A photodiode sensor is used to measure the output of a $300 \mathrm{~W}$ lamp kept $10 \mathrm{~m}$ away. The sensor has an opening of $2 \mathrm{~cm}$ in diameter. How many photons enter the sensor if the wavelength of the light is $660 \mathrm{~nm}$ and the exposure time is $100 \mathrm{~ms}$. (Assume that all the energy of the lamp is given off as light and $h=$ $6.6 \times 10^{-34} \mathrm{Js}$ )

1 $3.6 \times 10^{13}$
2 $2.8 \times 10^{13}$
3 $2.5 \times 10^{13}$
4 $1.8 \times 10^{13}$