Questions

Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment.

Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. This removes material that will either float or readily settle out by gravity. It includes the physical processes of screening, comminution, grit removal, and sedimentation.

Secondary treatment removes the soluble organic matter that escapes primary treatment. It also removes more of the suspended solids. Removal is usually accomplished by biological processes in which microbes consume the organic impurities as food, converting them into carbon dioxide, water, and energy for their own growth and reproduction.

Tertiary treatment includes removal of nutrients such as phosphorus and nitrogen and practically all suspended and organic matter from waste water.

Any factor limiting the size of a population whose effect is not dependent on the number of individuals in the population, then such factor is called Density Independent Factor. It is things that the organisms have no control over.

Here in the given options, food shortage and disease are factors that are dependent on the number of population but Floods have no dependency.

Some examples of density independent factors are :: Earth quake, fires, volcanic eruptions, floods, and  all natural calamities.

A Focus of an earthquake is the location where the earthquake begins. The ground ruptures at this spot, then seismic waves radiate outward in all directions.

At this focus point, the release of energy due to faulting actually occurs during an earthquake. The point directly above the focus on the surface is called Epicenter.

The focus is also called as Hypocenter as it is the synonym of the focus.

IC's (Integrated Circuits) also called as Chips or Microchips whose invention allowed computers to be smaller and smaller.

Madhya Pradesh is the leading producer of soybean in India.