Which of the following is not a unit of Energy?

The correct answer is Phon.  

• Phon is not a unit of Energy.
• Phon is a unit of the perceived loudness of sound for pure tones.

Units of heat:​

• A British thermal unit (BTU) is a measure of the heat content of fuels or energy sources.
  • It is the quantity of heat required to raise the temperature of one pound of liquid water by 1 degree Fahrenheit.
• kWh is used for electric power measurement.
• Joule is used for energy measurement.

Key Points

• The SI unit for temperature is the Kelvin.
• Celsius is a derived unit for temperature.
• The SI unit of energy/work is the joule.
• The SI unit of power is the watt (W).
• The SI unit for pressure is the pascal (Pa).