An LED light bulb has an efficiency of 80%. Does it violate the principle of energy conservation?

An LED light bulb with an efficiency of 80% does not violate the principle of energy conservation. The law of conservation of energy states that energy cannot be created or destroyed, only transformed. In the case of an LED light bulb, 80% of the electrical energy is converted into useful light, while the remaining 20% is converted into heat energy. The total energy input is still conserved, and the energy simply changes form. The fact that some energy is lost as heat is typical of all energy conversion processes. Therefore, the principle of energy conservation is fully upheld, as there is no loss of energy in the system, only its redistribution.

Related Questions:

  1. A car is moving with a constant speed along a straight road. Is there any work done on the car?
  2. Does the work done in raising a box up in a building depend upon how fast it is raised up? Through which path? To how much height?
  3. Work done on a body either speeds it up or slows it down. Keeping this in mind, explain how much work is done by centripetal force on an orbiting satellite?
  4. A car has kinetic energy ‘Eₖ’. By what factor would its kinetic energy change if its velocity is doubled?
  5. A bullet is fired from a gun, penetrates into a sand wall, and stops. Where does its kinetic energy go?
  6. How does using renewable energy sources contribute to reducing environmental impact compared to non-renewable sources?
  7. Will we eventually rely entirely on renewable energy sources? Why or why not?
  8. How can increasing the power of a machine impact its energy consumption?
  9. A perpetual engine has an efficiency equal to 1. Why will it not work?
  10. A person lifts a book and places it on a shelf. In which case is work done, and why?
  11. How does the work-energy theorem explain the relationship between work and kinetic energy?
  12. Why does a ball bounce lower after each bounce? Explain in terms of energy conversion.
  13. How does gravitational potential energy change when an object is taken from Earth to the Moon?
  14. A machine is said to be efficient. What does it mean in terms of input and output energy?
  15. Dynamics-II
  16. Pressure and Deformation in Solids
  17. Work and Energy
  18. Density and Temperature
  19. Magnetism
  20. Explain by drawing energy flow diagrams through steady-state systems such as a filament lamp, a power station, and a vehicle traveling at a constant speed on a level road.