Question

The maximum kinetic energy of emitted photoelectrons in a photoelectric cell is 7.5X10-19 J. What is the stopping 

Answer 1

$$W=eV$$

$$V=\frac{W}{e}=\frac{7.5*10^{-19}\:\rm J}{1.6*10^{-19}\:\rm C}=4.7\:\rm V$$