COMEDK202510 May 2025Morning ShiftPhysicsDual Nature of MatterActual
Emission of electrons from a metal plate illuminated with monochromatic electromagnetic radiation will always take place provided
Options
- AThe radiation is sufficiently intense
- BThe work function of the plate is less than the energy of a single photon and the plate is uncharged
- CThe plate is positively charged
- DThe plate is negatively charged
Correct answer
B. The work function of the plate is less than the energy of a single photon and the plate is uncharged
Step-by-step solution
According to Einstein's photoelectric equation, the kinetic energy of an emitted photoelectron is given by K_ max = h - , where h is the energy of the incident photon and is the work function of the metal. For emission to occur, the energy of the incident photon must be greater than the work function of the metal, i.e., h > . If h If the plate is uncharged, the condition h > is sufficient for emission. If the plate is negatively charged, the potential barrier for electron emission increases, making it harder for el