The question asks about the primary advantage of a pressure cooker. This relates to the principles of boiling point and cooking time. A pressure cooker works by increasing the pressure inside the cooking vessel, which in turn affects the boiling point of water and the rate at which food cooks.
C) Cooks food more quickly. This is the direct result of the increased boiling point of water under pressure, which allows food to cook at higher temperatures, thus reducing cooking time significantly.
This question asks about the pressure inside a pressure cooker during operation. Understanding the basic principle of how a pressure cooker works is key to answering this question.
Correct Option: C) Higher than atmospheric pressure
The question asks about the reason for the increase in boiling point inside a pressure cooker. This phenomenon is directly related to the physical properties of water and the effect of pressure on its boiling point.
B) Increased pressure: The sealed environment of a pressure cooker traps steam, leading to a significant increase in the internal pressure. This elevated pressure directly raises the boiling point of water, allowing food to cook faster at higher temperatures.
The question asks about the primary function of an impeller in a centrifugal pump. We need to understand how a centrifugal pump works and the role of its main components, especially the impeller, in converting energy.
The question asks about the primary utility of a diaphragm pump. We need to understand the operating principle and characteristics of diaphragm pumps to determine their most suitable applications.
Correct Option: A) Handling viscous fluids
Diaphragm pumps are positive displacement pumps. Their pumping action relies on the volumetric displacement created by the diaphragm's movement. This mechanism makes them highly effective at moving fluids with high viscosity, as the flow rate is largely independent of the fluid's internal resistance (viscosity) within typical operating ranges, unlike dynamic pumps (e.g., centrifugal pumps) whose performance drops significantly with increasing viscosity. Furthermore, the isolation of the fluid from the mechanical parts makes them ideal for abrasive or corrosive viscous fluids.
The purpose of a foot valve in a pump is to
Increase pressure
Prevent backflow
Reduce friction
Control flow rate
The question asks about the primary purpose of a foot valve in a pump system. Understanding the function of different pump components is crucial for competitive exams. A foot valve is a type of check valve located at the inlet of the suction pipe.
Correct Option: B) Prevent backflow. The primary function of a foot valve is to act as a non-return valve, preventing the pumped liquid from flowing back into the source when the pump is off. This ensures that the suction pipe remains full of liquid, keeping the pump primed and ready for immediate operation.