Two metals A and B have work functions 4 eV and 6 eV respectively. Which metal has lower threshold wavelength for photoelectric effect ? 

Explanation

To determine which metal has a lower threshold wavelength for the photoelectric effect, we can follow these steps:

### Step 1: Understand the relationship between work function and threshold wavelength
The threshold wavelength (\( \lambda_0 \)) is related to the work function (\( \phi \)) of a metal by the equation:
\[ \phi = \frac{hc}{\lambda_0} \]
where:
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