CBSE Class 9 Answered

Biogas plant:

Organic materials like dead parts of plants and waste materials of animals are decompsed in absence of oxygen so as to obtain Biogas. The plant where this process takes place is called biogas plant. Biogas is renewable source of energy. It is used as fuel in cooking food etc. 

 

Fire-extinguisher:

The fire-extinguisher are used to extinguish or control the small fires in emergency situations. Fire extinguishers usually contains compressed carbon-dioxide. They are bot used for  out-of control fire situations.

 

SONAR:

The full form SONAR is Sound Navigation And Ranging.

It is used in measuring the depths of sea-beds.

The SONAR is made receiver and transmitter. Transmitter transmits the ultrasonic waves and receiver detects the waves and calculates the depth of the sea using formula,

Depth of sea = speed x time/2

 

Dialysis of blood:

Dialysis is a process of removing excess of water, toxins and solutes from the blood of human beings whose kidneys cannot perform its functions naturally.

 

Sericulture:

Sericulture is also known as silk farming. In this farming, the commercial species of silkworms are cultivated to obtain the silk from them.

 

Pisciculture:

Pisciculture or fish farming is culture of raising the fishes like catla, rohu and silver carp in tanks or ponds usually for food.

 

Space telescope:

Space telescope is an instrument in tghe space used to observe the planets, galaxies and other astronomical objects.

Space telescopes are more convenient than ground-based telescopes as it overcome the problems of light pollution and distortion of electromagnetic radiations.

 

Radiography:

The process of obtaining the images of the internal organs for the purpose of medical examination is called radiogarphy. The process of radiography is carried by using beam of X-rays. 

 

Sonography:

The ultrasound is used to obtain the images of internal organs, muscles, joints and tissues. This technique is called sonography.