Photoelectric Effect: A photocathode having a work function of 2.8 eV is illuminated with monochromatic electromagnetic radiation whose photon energy is 4.0 eV. What is the threshold (cutoff) frequency for photoelectron production? (1 eV = 1.60 × 10-19 J, h = 6.626 × 10-34 J ? s)
A. 6.8 × 1014 Hz
B. 2.9 × 1014 Hz
C. 7.7 × 1014 Hz
D. 8.6 × 1014 Hz
E. 9.7 × 1014 Hz
Answer: A
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