A Single Slit Is Illuminated at Normal Incidence with a Parallel

Multiple Choice

A single slit is illuminated at normal incidence with a parallel beam of light having a wavelength of 411 nm.The entire central band of the diffraction pattern is observed at ±90°.The illumination is now replaced by a nonrelativistic beam of electrons,each having a kinetic energy of 980 eV.When this beam hits the slit at normal incidence,at what angle will the first minimum of the electron diffraction pattern occur? (h = 6.626 × 10^-34 J • s,m_el = 9.11 × 10^-31 kg,1 eV = 1.60 × 10^-19 J)

A) 0.095 mrad
B) 0.071 mrad
C) 0.046 mrad
D) 0.12 mrad
E) 0.14 mrad