Question

Which option is it...

Answer 1

y, z both will be doubled

Answer 2

we should keep some concepts in mind..
>Intensity of light determines the number of ejected electrons..more is intensity more the electrons emitted(according to Einstein explanation of photoelectric effect)
>K.E of electrons depends only on nature of surface and frequency of light
Since in above case intensity of light is doubled so y value be also doubled..and energy will remain same..
option b is right