The voltage applied to an electron microscope to produce electrons of wavelength `0.50 Å` is

What voltage must be applied to an electron microscope to produce electrons of wavelength 0.4 overset @A ?

What voltage must be applied to an elecron microscope to produce electrons of wavelength 0.4 overset @A ?

What voltage must be applied to an electron microscope to produce electron of wavelength 0.4overset@ A .

What voltage must be applied to an elect-non microscope to produce electrons of wavelength 0.4A ?

What voltage must be applied to an elect-non microscope to produce electrons of wavelength 0.4A ?

Calculate voltage to be applied to an electron microscope, so-as to produce electrons of wavelength 0.6 overset (@)(A) . Also, calculate the speed of the electrons.