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प्रश्न
Explain the experimental set-up of photoelectric effect.
उत्तर
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| Schematic of experimental set-up for photoelectric effect |
The experimental circuit to study the photoelectric effect is as shown in the figure.
It consists of an evacuated glass tube with a quartz window containing two photosensitive metal plates. One is the emitter E and another plate is the collector C.
The emitter and collector are connected to a voltage source whose voltage can be changed, and an ammeter is used to measure current.
A potential difference between E and C is measured by a voltmeter. Generally, C (anode) is at a positive terminal with respect to emitter E. When the anode potential (V) is positive, it accelerates the electrons. This potential is called accelerating potential. When the anode potential (V) is negative, it retards the flow of electrons. This potential is known as retarding potential. A source S of monochromahc light of sufficiently high frequency (λ ≤ 10 − 7) is used.
The applied P.D. between the plates can be changed with the help of potential divider arrangements by using a commulator key.
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संबंधित प्रश्न
If the frequency of incident light falling on a photosensitive material is doubled, then the kinetic energy of the emitted photoelectron will be ______.
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Given the following data for incident wavelength and the stopping potential obtained from an experiment on the photoelectric effect, estimate the value of Planck's constant and the work function of the cathode material. What is the threshold frequency and corresponding wavelength? What is the most likely metal used for emitter?
| Incident wavelength (in Å) | 2536 | 3650 |
| Stopping potential (in V) |
1.95 | 0.5 |
The electrons are emitted in the photoelectric effect from a metal surface.
As the intensity of incident light increases ______
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Draw a neat labelled diagram of a schematic of the experimental setup for the photoelectric effect.
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Draw a neat labelled diagram of photo-current as a function of accelerating potential for fixed incident intensity but different incident frequencies for the same emitter material.
The threshold frequency for a certain metal for photoelectric effect is 1.7 x 1015 Hz. When a light of frequency 2.2 x 1015 Hz is incident on the metal surface, the kinetic energy of the emitted photoelectrons is 3.3 x.10-19 J. Calculate Planck's constant.
