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NEET 1989 (AIPMT) · Photoelectric Effect: Einstein's Equation

Photoelectric Effect: Einstein's Equation question from NEET 1989 (AIPMT)

Q174NEET 1989 · AIPMTEasy

Photoelectric Effect: Einstein's Equation

Ultraviolet radiations of 6.2 eV falls on an aluminium surface. Kinetic energy of fastest electron emitted is (work function = 4.2 eV)

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Answer: (b)

  1. Kmax=E−ϕ=6.2−4.2=2 eVK_{max} = E - \phi = 6.2 - 4.2 = 2\text{ eV}
  2. Kmax=2×1.6×10−19=3.2×10−19 JK_{max} = 2 \times 1.6 \times 10^{-19} = 3.2 \times 10^{-19}\text{ J}
  3. So the answer is (b) 3.2×10−19 J3.2 \times 10^{-19}\text{ J}.
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