Questions

To create a simple electromagnet, you'll need a source of electricity, a conductor, and metal. Wrap insulated copper wire tightly around an iron screw or nail before connecting the wire to a battery, and watch as your new electromagnet picks up small metal objects.

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.

When exports are greater than imports, net exports are positive and similarly, when imports are greater than exports, net exports are negative.

When a country imports goods, it buys them from foreign producers. The money spent on imports leaves the economy, and that decreases the importing nation's GDP.

Guglielmo Marconi, an Italian invetor invented Radio in 1890's.

The functions performed by trade unions can be classified into two groups: 

i.) Militant Functions

ii.) Fraternal Functions

Militant functions :

These activities include strike, lock outs, gherao etc which means putting up a fight with the management. Hence, they are called militant functions. They are carried out for following purposes: 

a.) Rise in wages

b.) Rise in the status of workers

c.) Protection against injustice

Fraternal functions :

These functions are carried out by the trade unions for the welfare of their employees which includes: 

a.) Measures to boost up the workers’ morale

b.) Foster self confidence

c.) Develop sincerity and discipline

d.) Protection to women workers against discrimination