A Photocathode Whose Work Function Is $2.9 \mathrm { eV }$

Multiple Choice

A photocathode whose work function is $2.9 \mathrm { eV }$ is illuminated with white light that has a continuous wavelength band from $400 \mathrm {~nm}$ to $700 \mathrm {~nm}$ . What is the range of the wavelength band in this white light illumination for which photoelectrons are not produced? $( c = 3.00 \times 10^8 \mathrm {~m} / \mathrm { s } , h = 6.626$ $\times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } , 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J}$ )

A) $480 \mathrm {~nm}$ to $700 \mathrm {~nm}$
B) $430 \mathrm {~nm}$ to $700 \mathrm {~nm}$
C) $430 \mathrm {~nm}$ to $480 \mathrm {~nm}$
D) $400 \mathrm {~nm}$ to $480 \mathrm {~nm}$
E) $400 \mathrm {~nm}$ to $430 \mathrm {~nm}$