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In a photoelectric experiment, metals P, Q, and R emit photoelectrons with maximum kinetic energies EP, EQ, and ER, respectively, such that EP = 2EQ = 2ER. The same monochromatic light source is used for metals P and Q, while a different monochromatic light source is used for metal R. The work functions of metals P, Q, and R are 4.0 eV, 4.5 eV, and 5.5 eV, respectively. What is the energy of the photons incident on metal R, in eV?

1. 5
2. 5.5
3. 6
4. 6.5

Correct answer: 6

Solution

The energy of the photons incident on metal R is calculated using the photoelectric equation and the given kinetic energy relationships, resulting in a photon energy of 6 eV.

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