Question

The minimum intensity of white light that our eyes can perceive is about 0.1 nWm⁻². Calculate the number of photons of this light entering our pupil (area 0.4 cm²) per second.

Write Einstein's photoelectric equation. How did Millikan prove the validity of this equation ?

What are matter waves ? A particle of mass m and charge q is accelerated from rest through a potential difference V. Obtain an expression for de Broglie wavelength associated with the particle.

Monochromatic light of frequency 5.0 × 10¹⁴ Hz is produced by a source of power output 3.315 mW. Calculate : (1) energy of the photon in the beam (2) number of photons emitted per second by the source