प्रकाश के फोटॉन सिद्धांत का उपयोग करके प्रकाश विद्युत प्रभाव की सफल व्याख्या किसने की थी?

A bulb is rated at 150 W and converts 8% of its input energy into light. If the energy of one photon is 4.42 × 10-19 J, how many photons are emitted by the bulb per second?

For a metal with a work function of 6.6 eV, which of the following wavelengths of incident radiation will NOT cause the photoelectric effect? (Take Planck's constant h = 6.6 × 10-34 J s and c = 3 × 108 m/s)