The Sankey diagram shows the energy transfers in an LED light bulb. (look at the attached photo)

B)20%

Explanation:

only the 2j of energy is getting used out of 10j.all other 8j are wasted as heat.

therefore the efficiency=2/10*100=20

  the unit of the measure =

explanation:

  the property that is quantified by the energy needed per of material to raise the temperature by one.

  si unit of energy = joule (j)

  si unit of temperature = kelvin (k)

  si unit of mass of material = kilogram (kg)

the property that is quantified by the energy needed per of material to raise the temperature by one is called specific heat.

the unit of specific heat is