## Question

The threshold frequency *v _{0}* for a metal is 7.0 × 10

^{14}s

^{–1}. Calculate the kinetic energy of an electron emitted when radiation of frequency

*v*= 1.0 × 10

^{15}s

^{–1}hits this metal.

### Solution

According to Einstein’s equation, K.E. of the photoelectron emitted

**.**

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