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12th ICSE
IMPORTANT
Earn 100

Which of the following radiations will be most effective for electron-emission from the surface of zinc? Microwave, infrared, ultraviolet.

Important Questions on Photoelectric Effect

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12th ICSE
IMPORTANT
ISC Physics Class 12, Part-2>Chapter 10 - Photoelectric Effect>QUESTIONS>Q 22
It is harder to remove photoelectrically a free electron from copper than from sodium. Which metal has a greater work function? Which has higher threshold wavelength?
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12th ICSE
IMPORTANT
ISC Physics Class 12, Part-2>Chapter 10 - Photoelectric Effect>QUESTIONS>Q 23
Radiation of frequency 1015 Hz falls on surfaces P, Q and R. The surface P does not emit photoelectrons, Q emits photoelectrons of zero kinetic energy whereas R emits photoelectrons having kinetic energies. What conclusions would you draw?
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12th ICSE
IMPORTANT
ISC Physics Class 12, Part-2>Chapter 10 - Photoelectric Effect>QUESTIONS>Q 24
If the maximum kinetic energy of electrons emitted by a photo-cell is 4 eV, what is its stopping potential?
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12th ICSE
IMPORTANT
ISC Physics Class 12, Part-2>Chapter 10 - Photoelectric Effect>QUESTIONS>Q 25
When photons of energy 5.0 eV fall on the surface of a metal, the emitted photoelectrons are stopped by a cut-off potential of 3.5 volt. What is the work function of the metal?
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12th ICSE
IMPORTANT
ISC Physics Class 12, Part-2>Chapter 10 - Photoelectric Effect>QUESTIONS>Q 26
Some photographic plates are not affected by red light, but are immediately blackened by white light why?
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12th ICSE
IMPORTANT
ISC Physics Class 12, Part-2>Chapter 10 - Photoelectric Effect>QUESTIONS>Q 27
Electrons are emitted from a surface when green light is incident on it, but no electrons are ejected when yellow light falls on the surface. Do you expect electrons to be ejected when the surface is exposed to red light?
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12th ICSE
IMPORTANT
ISC Physics Class 12, Part-2>Chapter 10 - Photoelectric Effect>QUESTIONS>Q 27
Electrons are emitted from a surface when green light is incident on it, but no electrons are ejected when yellow light falls on the surface. Do you expect electrons to be ejected when the surface is exposed to blue light?
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12th ICSE
IMPORTANT
ISC Physics Class 12, Part-2>Chapter 10 - Photoelectric Effect>QUESTIONS>Q 28
Photons of energies twice and five times the work function of a metal fall successively on the metal surface. What is the ratio of the maximum velocities of photoelectrons emitted in the two cases?