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Question
The equation E = pc is valid
Options
for an electron as well as for a photon
for an electron but not for a photon
for a photon but not for an electron
neither for an electron nor for a photon
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Solution
for a photon but not for an electron
The equation E = pc is valid for a particle with zero rest mass. The rest mass of a photon is zero, but the rest mass of an electron is not zero. So, the equation will be valid for photon, and not electron.
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