Question

Explain what is meant by degraded energy:
(A) Reduced energy after conversion
(B) Unusable energy due to lack of facilities
(C) When energy in one form is converted to another, part of the energy has to be expelled into the environment. This is called degraded energy
(D) None of these

Answer 1

Hint: Using energy to do work is not a 100% efficiency process. This means that the energy is lost every time there is a conversion. This means that the energy basically got degraded because some of it was lost.

Complete step by step answer
Degraded energy is the energy that is produced by a system which is converting one form of energy into the other. The energy that is released into the environment or that isn’t useful is known as degraded energy.

Hence, Option (c.) is the correct answer.

Additional information We know that energy of a system is always conserved but we can transform it from one form to another. During these transformations, it is not necessary that all forms of energies be interconvertible. As a result, some energy is lost in the environment mainly in the form of heat. This energy is not of any use so it can be called ‘dead’ or degraded energy.
The second law of thermodynamics states that it is impossible for a self-acting machine to transfer heat from a cooler body to a hotter one without any aid of an external agency. This is quite similar to what we mentioned earlier. Therefore, it won’t be wrong to say that the second law of thermodynamics can also be known as the law of degradation of energy.

Note
The question is fact based. In case one doesn’t know the correct option, they can review the options and choose the seemingly most correct.
Option A: Gives a hint that degraded energy means that the remaining energy. But even if there is usable energy that doesn’t mean that it is degraded
Option B: Loss of energy during conversion can be reduced by improving machinery. But the energy which is lost however primarily due to lack of facilities or poor infrastructure is not degraded energy.
Option C: Energy is always going to be lost, there cannot be a machine giving out 100% efficiency. So even with best efficiency if there is loss of energy, this is called degraded energy. This option makes the most sense. Hence can be chosen as the correct option