Is photoelectric emission possible at all frequencies? Give reason for your answer?

An image of the sun is formed on the metal surface of the photoelectric cell and it produces of current. The lens forming the image is then replaced by another of the same diameter but only half in focal length. a. What will be the effect on the photoelectric current? b. Is photoelectric emission possible at all frequencies ? c. If not give your explanation.

Is a solution always a liquid ? Give reasons for your answer .

Is phenylketonuria related to albinism? Give reason for your answer.

Using Einstein.s photoelectric equation show that photoelectric emission is not possible if the frequency of incident radiation is less than the threshold frequency

In photoelectric emission, a radiation whose frequency is 4 times threshold frequency of a certainn metal is incident on the metal. The an the maximum possible velocity of the emitted electron will be…………………