• # question_answer 3) The maximum energy${{K}_{\max }}$of photoelectrons emitted in a photoelectric cell is measured using lights of various frequencies v. The graph in figure shows how${{K}_{\max }}$ varies with v. The slope of the graph is equal to A) the charge of an electronB) the charge to mass ratio of an electronC) the work function of the emitter in the cellD) Planck's constant.

Since ${{K}_{\max }}=h(v-{{v}_{0}}),$the slope of the graph of ${{K}_{\max }}$against v is h, the plank?s constant Hence, the correction option is (d). Let radius of the nth orbit of $B{{e}^{++}}=R$ Now,$r=\frac{{{a}_{0}}{{n}^{2}}}{z},$ where ${{a}_{0}}$is the radius of the first orbit of hydrogen atom.