The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately

The work function of a substance is 4.0 eV. The longest wavelength of

1.	The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately
Answer» 540 nm 400 nm 310 nm 220 nm Solution :`phi_(0)=hv_(0)=(HC)/(lamda_(0))` and if `phi_(0)` be in eV then `phi_(0)=(hc)/(elamda_(0))` `therefore lamda_(0)=(hc)/(e*phi_(0))=(6.63xx10^(-34)xx3xx10^(8))/(1.6xx10^(-19)xx4.0)=3.1xx10^(-7)=310nm`.

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The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately

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