CAPE Physics Unit 2 · 2017 · Paper 1 · Question Q39

Electromagnetic radiation is incident on a metal surface whose work function is 6.4 \times 10^{-19}\text{ J}. The value of the minimum frequency of radiation which will cause electrons to be emitted is

1. (A)3.1 \times 10^{-7}\text{ Hz}
2. (B)9.7 \times 10^{14}\text{ Hz}
3. (C)6.4 \times 10^{15}\text{ Hz}
4. (D)9.6 \times 10^{16}\text{ Hz}