Question

The max ke of electron is 3ev what is its stopping potential

Answer 1

Relation between kinetic energy in terms of stopping potential is given by:

K.E. = eV0 
where e= charge on the electron.
         V0= stopping potential
given kinetic energy of an electron is 3eV.
To convert it into  joule we multiply  it by e. (As 1 eV = 1.6 X 10-19J)

therefore 3e = eV​0 
V0= 3volts
Hence stopping potential is 3 volts.
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