कार्य, ऊर्जा और शक्ति | Work, Energy & Power | NEET 2021 | Physics | Doubtnut | Vipin Sir

Class 11 NEET 2020 - Revision In 30 Days | Work Power Energy - Quick Revision | NEET Physics | Important Questions

Work(कार्य )|Power(शक्ति)|Energy(ऊर्जा)|Summary

Work, Power And Energy | Quick Revision + Important Questions | JEE Mains 2020 / NEET 2020 | Physics

Work (काम)|Power|Energy(ऊर्जा)|OMR

Exercise Questions (प्रश्न)|Kinetic Energy (गतिज ऊर्जा)|Relation Between Momentum And Kinetic Energy(संवेग तथा गतिज ऊर्जा में संबंध)|Potential Energy (स्थितिज ऊर्जा)|Work Energy Theorm (कार्य ऊर्जा प्रमेय)|OMR

WORK AND ENERGY | QUICK REVISION | Previous Year Questions Explained | JEE MAINS/NEET 2020 Physics

A metal foil is at a certain distance from an isotropic point source that emits energy at the rate P. Let us assume the classical physics to be applicable. The incident light energy will be absorbed continuously and smoothly. The electrons present in the foil soak up the energy incident on them. For simplicity , we can assume that the energy incident on a circular path of the foil with radius 5xx10^(-11) m (about that of a typical atom ) is absorbed by a single electron. The electron absorbs sufficient energy to break through the binding forces and comes out from the foil. By knowing the work function, we can calculate the time taken by an electron to come out i.e., we can find out the time taken by photoelectric emission to start. As you will see in the following questions, the time decay comes out to be large, which is not practically observed. The time lag is very small. Apparently, the electron does not have to soak up energy . It absorbs energy all at once in a single photon electron interaction. If power of the source P is 1.5 W and distance of the foil from the source is 3.5 m, the energy received by an electron per second is

Work,Power,Energy(कार्य,शक्ति और ऊर्जा)|Questions (प्रश्न)|OMR|Summary

Work,Power,Energy(कार्य,शक्ति और ऊर्जा)|Questions (प्रश्न)|OMR|Summary