Threshhold frequency is defined as the minimum light frequency necessary to start photo-electric emission from the surface. This frequency is just effecient enough to emit electrons without any additional force or energy. this minimum frequency creates the necessary result that is sought by the person. The photo electric emission for certain metals can occir with threshhold frequency. The importance of this threshhold frequency lies in the fact that this has been used to create numerous instruments like amplifiers for use of people.
Answer:
the awnser is A becuse the hair help.
A method of investigation in which a problem is first identified and observations, experiments, or other relevant data are then used to construct or test hypotheses that purport to solve it.
