Physics > Basic Modern Physics > 5.0 Photoelectric Effect
Basic Modern Physics
1.0 Photon theory of light
2.0 Characteristics of photon
3.0 Wave Particle Duality
4.0 Emission of electrons
5.0 Photoelectric Effect
5.1 Laws of Photoelectric emission
5.2 Photoelectric equation
5.3 Photoelectric Current
5.4 Stopping potential
5.5 Graph between $K{E_{max}}$ and frequency
6.0 Radiation Pressure And Force
7.0 Photon Density
8.0 Force exerted by a light beam on a surface
9.0 Early Atomic Structures
10.0 Bohr Model of The Hydrogen Atom
10.1 Radius of Orbit
10.2 Velocity of electron in the $n^th$ orbit
10.3 Orbital frequency of electron
11.0 Energy of electron in the $n^{th}$ orbit
12.0 Basic Definitions
13.0 Atomic Excitation
5.4 Stopping potential
5.2 Photoelectric equation
5.3 Photoelectric Current
5.4 Stopping potential
5.5 Graph between $K{E_{max}}$ and frequency
10.2 Velocity of electron in the $n^th$ orbit
10.3 Orbital frequency of electron
Clearly on increasing $V$ when negative, the force of repulsion to the electron gets increased and the number of electrons reaching plate decreases. At certain ${V_0}$ electrons possessing the $K{E_{max}}$ are also get stopped. Hence the current in the circuit reduces to zero. This potential is known as stopping potential(${V_0}$). $$e{\nu _0} = \phi ...(2)$$
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| Photo current $i$ is a function of the anode potential for a constant light frequency ${\nu _1}$, the stopping potential ${V_0}$ is independent of the light intensity $I$. | Photo current $i$ is a function of the anode potential for two different light frequency ${\nu _1}$ and ${\nu _2}$ with the same intensity. The stopping potential increase as the frequency increases. |
Since from (2) as ${V_0}$ depends on $\phi $ which in turn depends on ${\nu _1}$ of the incident light,hence stopping potential remains same as frequency remains the same. On increasing intensity more number of photos are allowed to incident on the metal surface, hence more electrons are emitted which increases the photo current. | Since from (2) as ${V_0}$ depends on $\phi $ which in turn depends on ${\nu _1}$ of the incident light,hence stopping potential increase as the frequency increases. However as intensity remains the same, photo current remains the same. |
