Final answer:
In a stored-pressure extinguisher, compressed air or inert gas is used to discharge the agent when the handle is pressed. The pressure and volume of the gas follow the combined gas law, which dictates that pressure rises with a reduction in volume or an increase in temperature. Therefore, the correct answer is d.stored-pressure
Step-by-step explanation:
In a stored-pressure extinguisher, compressed air or inert gas within the container forces the agent out of the extinguisher nozzle when the operator presses the handle. The principle behind this is based on the gas laws, where the compressed gas follows the combined gas law, which relates pressure, volume, and temperature.
When the gas is compressed, the pressure increases, and if the temperature rises, pressure also increases. These factors are crucial in the design of such extinguishers to prevent rupture due to excessive pressure and to ensure effective dispersal of the extinguishing agent.
For example, if a fire extinguisher is filled with CO₂ at a high pressure and the temperature increases significantly, the internal pressure will rise.
This principle is demonstrated by safety standards in the design of gas cylinders, which often have a safety factor to accommodate pressure changes due to temperature fluctuations.
Pressure gauges and other such monitoring devices are important to ensure that the cylinder remains within safe operational limits. The application of physics and chemistry in these devices is critical for their safe and efficient operation.
Therefore, the correct answer is d.stored-pressure