Question

Write notes on :

(a) Magnetic energy

(b) Electrical energy − generation and uses.

(c) Gobar gas − production and uses.

Answer 1

(a) Magnetic energy:

Bring a magnet near an iron nail. The iron nail gets attracted towards the magnet and starts moving. The attraction of the magnet causes the movement of the nail. Therefore, the magnet must possess some kind of energy that does the work on the nail. This energy is called magnetic energy. Magnetic energy is broadly used in industries where heavy metal pieces are shifted from one place to another. In Japan, magnetic energy is used even for running high-speed trains.

(b) Electrical energy − generation and uses:

In a hydroelectric power plant, the potential energy of water at a higher level is converted to kinetic energy of the water by letting it flow at a faster rate. The fast falling water rotates the turbine of the generator. Thus, kinetic energy of the water is converted into mechanical energy of the turbine. The axle of the turbine is connected to the armature of the electric generator. Thus, the rotating turbine now rotates the armature in the magnetic field of the generator. As a result, mechanical energy of the rotating system of the generator is converted into electrical energy of the generator. Thus, we have electrical energy as output from the hydroelectric power plant.

Electrical energy is used in cities, homes, schools and various companies.

(c) Gobar gas − production and uses:

In India, biogas is commonly known as “gobar gas”.

Gobar gas production:

Biogas technology provides an alternate source of energy in rural India. It is a more efficient and developed form of fuel.

It uses a thick mixture of cattle waste and kitchen garbage. This is fed into an inlet chamber. The microorganisms present in the digester tank are mainly methanogens.

These methanogens decompose the organic waste (slurry) anaerobically to produce methane and some carbon dioxide. A mixture of these gases is known as gobar gas.

It is used for cooking, lighting of lamps and generating electricity.