Can coefficient of performance of a refrigerator be greater than unity? The coefficient of performance (COP) of refrigeration is always more than 1. Hence option (a) is correct. COP is the ratio of heat extracted from the refrigerator to the work done on the refrigerant. Thus it is but obvious that the value of COP […]
What are the machines used in agriculture?
What are the machines used in agriculture? Steam-powered: Stationary steam engine. Portable engine. Traction engine (e.g. Agricultural engine, Ploughing engine, Steam tractor) Hog oiler. Reaper (replaced by the Stripper and Reaper-binder) Winnowing machine/Winnowing-fan. Threshing machine (replaced by the combine harvester) Drag harrow. How are the machines useful for farmers? Modern irrigation relies on machinery. Engines, […]
What are thermodynamic properties?
What are thermodynamic properties? Thermodynamic properties are defined as characteristic features of a system, capable of specifying the system’s state. If the units were changed from per mass to, for example, per mole, the property would remain as it was (i.e., intensive or extensive). What are independent properties in thermodynamics? Two properties are independent if […]
What is the understory layer of the rainforest?
What is the understory layer of the rainforest? The understory is the underlying layer of vegetation in a forest or wooded area, especially the trees and shrubs growing between the forest canopy and the forest floor. Plants in the understory comprise an assortment of seedlings and saplings of canopy trees together with specialist understory shrubs […]
What happens to the viscosity of a liquid with decrease in temperature?
What happens to the viscosity of a liquid with decrease in temperature? The former effect causes a decrease in the shear stress while the latter causes it to increase. The result is that liquids show a reduction in viscosity with increasing temperature. With high temperatures, viscosity increases in gases and decreases in liquids, the drag […]
What is Smith chart in transmission lines?
What is Smith chart in transmission lines? The Smith chart is a chart of normalized impedances (or admittances) in the reflection coefficient plane. As such, it allows calculations of all parameters related to transmission lines as well as impedances in open space, circuits, and the like. How does a Smith chart work? The Smith Chart […]
What are knowledge based systems explain with an example?
What are knowledge based systems explain with an example? A knowledge-based system (KBS) is a form of artificial intelligence (AI) that aims to capture the knowledge of human experts to support decision-making. Examples of knowledge-based systems include expert systems, which are so called because of their reliance on human expertise. Which system can be seen […]
What are ways to reduce greenhouse gas emissions?
What are ways to reduce greenhouse gas emissions? The following is a list of steps YOU can take to reduce greenhouse gas emissions: Reduce, Reuse, Recycle. Use Less Heat and Air Conditioning. Replace Your Light Bulbs. Drive Less and Drive Smart. Buy Energy-Efficient Products. Use Less Hot Water. Use the “Off” Switch. Plant a Tree. […]
What do sediment cores tell us?
What do sediment cores tell us? These cores are long cylinders of the earth’s crust, drilled up from beneath the seafloor. When the cores shown here are arranged end-to-end, they show a glimpse of the Earth’s past geology and climate. What discoveries were made by Ocean Drilling? Major Scientific Accomplishments Scientific ocean drilling has advanced […]