Final answer:
A fire extinguisher that requires the operator to manually pump to increase the pressure is known as a manual pump fire extinguisher. The correct answer is option a.
Step-by-step explanation:
A fire extinguisher that requires the operator to apply pressure to a pump to increase the pressure within the container and force the extinguishing agent out of the nozzle is known as a manual pump fire extinguisher. This method aligns with descriptions of how pressure increases within a rigid container when the amount of gas is increased by introducing additional air without changing the volume of the container, as with certain types of fire extinguishers or air pumps used for sports equipment.
It is important to understand that pressure is directly related to the amount of gas and its volume, as per the gas laws. When the volume of a container remains constant and more gas molecules are added, as described with the canister or fire extinguisher scenario, the pressure inside increases because more molecules are colliding with the walls of the container.
In this context, if you were to touch the nozzle of an extinguisher after use, you might notice it feels cold. This is because the escaping gas molecules draw energy from their surroundings, causing a temperature drop. The principles described here are pertinent to real-world applications and safety protocols related to containers subject to changes in pressure and temperature, such as fire extinguishers or gas cylinders.
The correct answer to the question is: a. manual pump.