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Light of frequency 1.5 times the threshold frequency ν₀ is incident. If frequency is halved, no photoelectric emission will take place. Which of the following is correct?

1. As E = 12400 / λ
2. λ = 12400 / 4 = 3100 Å
3. λ = 310nm
4. Both answers are correct

Correct answer: Both answers are correct

Solution

The frequency of light is initially 1.5 times the threshold frequency, so halving it makes it 0.75ν₀, which is below the threshold frequency. This means no photoelectric emission occurs. Both the energy-wavelength relation and the calculated wavelength are correct.

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