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

question 105

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 \(430 \mathrm {~nm}\)

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Definitions:

Peripheral

Relating to or situated on the edge or periphery of something, often considered less important than the core.

Parasympathetic

Referring to the part of the autonomic nervous system that conserves energy as it slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles.

Somatic

Relating to, or affecting the body, especially as distinguished from the mind or consciousness.

Endorphins

Natural, pain-relieving chemicals produced by the body that also contribute to feelings of pleasure and well-being.