Limit of Resolution

Q. Two point white dots are $1\text{mm}$ apart on a black paper. The are viewed by the eye of pupil diameter $3\text{mm}$. Approximately, the minimum distance(in $mt$ at which these dots can be resolved by the eye is
Take wavelength to be $500\text{nm}$

Q.

Stopping potential for photoelectrons

1. Does not depend on the frequency of the incident light

2. Does not depend upon the nature of the cathode material

3. Depends on both the frequency of the incident light and nature of the cathode material

4. Depends upon the intensity of the incident light