Who discovered photo electric effect ?

Who discovered thermoelectric effect?

If intensity of incident light is increased in photo electric effect then which of the following is true ?

If intensity of incident light is increased in photo electric effect then which of the following is true ?

The work function of a metal is 4 eV if 5000 Å wavelength of light is incident on the metal. Is there any photo electric effect ?

Modern Physics photo electric effect

Modern Physics photo electric effect

Who discovered the magnetic effect of an electric current ?