A Photocathode That Has a Work Function Of $2.4 \mathrm { eV }$

Multiple Choice

A photocathode that has a work function of $2.4 \mathrm { eV }$ is illuminated with monochromatic light having photon energy $3.5 \mathrm { eV }$ . What is the wavelength of this light? $\left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \right.$ . $\mathrm { s } , 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J}$ )

A) $350 \mathrm {~nm}$
B) $300 \mathrm {~nm}$
C) $410 \mathrm {~nm}$
D) $330 \mathrm {~nm}$
E) $380 \mathrm {~nm}$