Importance of Maximising the Efficiency of Devices
- A device is a tool or an equipment constructed for a specific purpose. An electric drill is a device used to drill holes. A forklift is constructed to lift heavy objects vertically.
- A device converts input energy to useful output energy. However, during the process, some of the energy is wasted in the form of heat and sound that is eventually lost to the surroundings.
- The efficiency of a device is always less than 100%.
- Maximising the efficiency of a device during the transformation from input energy into useful output energy can reduce wastage of energy. This will help in conserving energy resources.
- When less energy is wasted, the cost of operating a device is reduced.
- Figure (b) shows an energy transfer diagram, which is also known as a Sankey diagram. It shows how the input energy, in the form of chemical energy stored in the battery, is converted into useful output energy in the form of light. However, a bigger percentage of the input energy is wasted as heat that is dissipated to the surroundings.
- Generally, devices such as levers and pulleys that convert one kind of mechanical energy into another are more efficient than the ones that convert different forms of energy such as chemical energy into mechanical energy.
- The efficiency of a device can be increased in the following ways:
(a) Reduce friction and heat loss. This can be done by using quality lubricants. An example is the usage of quality lubricating oil in car engines.
(b) Improve the design of the device to reduce vibration and sound.
(c) For moving devices, like cars and aeroplanes, a streamlined body will reduce heat loss.