A photo electric setup uses a 100 watt bulb of blue colour. If I bring the bulb closer to the plate what will happen to the stopping potential and why? According to classical model, it will become more ___________ (positive/negative)
A photo electric setup uses a 100 watt bulb of blue colour. If I bring the bulb closer to the plate what will happen to the stopping potential and why? According to classical model, it will become more ___________ (positive/negative)
The correct option is B Negative
So when you bring the light source closer to the plate the energy falling per unit time will increase.
According to the classical model the electrons will receive more energy per unit time and hence when they overcome the work function and pop out they will have a higher kinetic energy as compared to the previous case.
Similarly the maximum Kinetic energy possessed by an electron will increase as compared to the previous case.
And since the maximum kinetic energy has increased now we will require a higher negative potential to stop this electron. Thus the stopping potential will increase in negative direction.
Negative
So when you bring the light source closer to the plate the energy falling per unit time will increase.
According to the classical model the electrons will receive more energy per unit time and hence when they overcome the work function and pop out they will have a higher kinetic energy as compared to the previous case.
Similarly the maximum Kinetic energy possessed by an electron will increase as compared to the previous case.
And since the maximum kinetic energy has increased now we will require a higher negative potential to stop this electron. Thus the stopping potential will increase in negative direction.
