If the frequency v of the incident light is less than the cut-off frequency v0, no matter how strong the light intensity of the incident light is, no photoelectric effect can be produced. The cutoff frequency is related to the cathode material, and v0 of different metal materials is generally different. This frequency v0 is called the cut-off frequency, also known as the red limit frequency, the limit frequency. For a certain metal material, only when the frequency of the incident light is greater than a certain frequency v0, the electrons can escape from the metal surface to form a photocurrent. But not all frequencies of incident light can cause photoelectric effect. Cut-off frequency photoelectric effect When light hits the metal surface, electrons escape from the metal surface. The frequency range between the two cutoff frequencies is called the passband. Since 20lgA () =-3dB, the solution is A () = 10 ^ -0.15 = 0.7079457841 / 2, and because A () = | H (J) |, then | H (j) | ^ 2 = 1/2 There is a cut-off frequency at the high-frequency end and the low-frequency end, respectively called the upper cut-off frequency and the lower cut-off frequency. Chinese name Cut-off frequency Foreign name cut-off frequency Node value -3dB Cut- off frequency : Use the modulus of the system function to represent the amplification of the circuit. It is used to explain the frequency characteristic index. That is to say, the frequency response characteristic is the cut-off frequency at the -3dB point. When the amplitude of the input signal is kept unchanged, the frequency is changed to reduce the output signal to 0.707 times the maximum value.

What is cutoff frequency