A Photocathode Having a Work Function of 2

question 26

Multiple Choice

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

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