if the K.E of electron is Increased by 4 times then Broglie wavelength associated with it would become????????

de broglie wavelength (lamda)L=  h/(2mKE)^{1/2                 ..............1}          

 here h is planks constant, m is mass of electron  & KE is kinetic energy...

     from eq 1

                      L(lamda) is inversly proportional to (KE)^1/2

                    L/L_{1   =   {(KE)f /(KE})_i}^1/2          

(KE)_{f =} 4(KE)i   (given)

 so    L_{/L1 = 2   or}

        L₁ = L/2

 it means de broglie wavelength of electron is decreased to half times the  initial value....

According to De BROGLIE,

wavelength=h/root 2Em

where h....Planck constant

E.... Kinetic energy, m= mass of electron

Thus, when kinetic energy associated with electron is increased four times, then wave length would become half of the initial value.