Question

The efficiency of a furnace is generally defined as:

• A. Energy lost / energy input
• B. Energy input / energy loss
• C. Useful heat / heat supplied
• D. Mass of fuel / heat output

Hint:

Efficiency measures how well a system converts input energy into useful work or output. In the case of a furnace, it is defined as the ratio of useful heat to the total heat supplied.

Answer 1

The Correct Option is C

The efficiency of a furnace is a measure of how effectively the furnace converts the energy it consumes (input) into useful energy (output). It is generally defined as the ratio of useful heat obtained from the furnace to the total heat supplied to it. The correct formula for furnace efficiency is: \[ {Efficiency} = \frac{{Useful Heat}}{{Heat Supplied}} \] Where:
- Useful Heat refers to the energy that is actually put to work, i.e., the heat energy that is used for the intended purpose.
- Heat Supplied is the total heat energy input into the furnace from all sources.
This formula measures the proportion of energy that is successfully converted into useful output. Higher efficiency indicates that more of the input energy is converted into useful work rather than being lost.
- Energy lost / energy input is not the correct definition of efficiency but represents energy loss ratio, which is the inverse of efficiency.
- Energy input / energy loss is also incorrect, as it doesn't reflect the useful output of the furnace.
- Mass of fuel / heat output is irrelevant in the context of calculating furnace efficiency, as it relates to fuel consumption and not heat conversion.
Thus, the correct definition of furnace efficiency is Useful heat / heat supplied.