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प्रश्न
Give the applications photocell.
उत्तर
Applications of photocells:
- Photocells have many applications, especially as switches and sensors.
- Automatic lights that turn on when it gets dark use photocells, as well as street lights that switch on and off according to whether it is night or day.
- Photocells are used for the reproduction of sound in motion pictures and are used as timers to measure the speeds of athletes during a race.
- Photocells are used to measure the intensity of the given light and to calculate the exact time of exposure.
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संबंधित प्रश्न
In photoelectric emission, a radiation whose frequency is 4 times threshold frequency of a certain metal is incident on the metal. Then the maximum possible velocity of the emitted electron will be
A light of wavelength 500 nm is incident on a sensitive metal plate of photoelectric work function 1.235 eV. The kinetic energy of the photoelectrons emitted is (Take h = 6.6 × 10–34 Js)
How will you define threshold frequency?
Define stopping potential.
What is a surface barrier?
List out the laws of photoelectric effect.
Give the construction and working of photo emissive cell.
Calculate the maximum kinetic energy and maximum velocity of the photoelectrons emitted when the stopping potential is 81 V for the photoelectric emission experiment.
Calculate the energies of the photons associated with the following radiation:
- violet light of 413 nm
- X-rays of 0.1 nm
- radio waves of 10 m
At the given point of time, the earth receives energy from the sun at 4 cal cm–2 min–1. Determine the number of photons received on the surface of the Earth per cm2 per minute. (Given: Mean wavelength of sunlight = 5500 Å)
