In a photoelectric experiment using light of wavelength 450 nm, which stopping potential would be observed?

2.75 volts
4.5 volts
0.45 volts
0.25 volts

Correct answer: 0.45 volts

Solution

The stopping potential is the potential needed to stop the most energetic photoelectrons, so it is directly related to their maximum kinetic energy. For the given experiment, the correct observed value is 0.45 V. This corresponds to the option with the smallest positive stopping potential among the choices.

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