Several factories were pouring their wastes in rivers A and B. Water samples were collected from these two rivers. It was observed that sample collected from river A was acidic while that of river B was basic. The factories located near A and B are

An aqueous solution 'A' turns phenolphthalein solution pink. On addition of an aqueous solution 'B' to 'A, the pink colour disappears. The following statement is true for solution 'A' and 'B'.

In which of the following, the identity of initial substance remains unchanged?

A diagram of traditional water harvesting system is given below:

The statement which defines the system and its parts is Piss

(a) This is an ideal setting of the Khadin system and A= Catchment area; B = Saline area & C= Shallow dugwell

(b) This is an ideal setting of the Shallow dugwell system and A= Catchment area; B= Saline area and C= Khadin

(c) This is an ideal setting of Catchment area and A=K hadin, B= Saline area and C= Shallow dugwell

(d) This is showing Saline area and A= Catchment area; B= Khadin and C= Shallow dugwell 1

OR

The major ill effect of mono culture practice in forests is on the

(a) biodiversity which faces large destruction

(b) local people whose basic needs can no longer be met from such forests

(c) industries

(d) forest department

Answer question numbers 13(a) to 13(d) on the basis of your understanding of the following paragraph and the related studies concepts.

The Tehri dam is the highest dam in India and one of the highest in the World. The Tehri dam withholds a reservoir of capacity 4.0 km³ and surface area 52 km². It is used for irrigation, municipal water supply and the generation of 1000 MW of hydroelectricity.

The Tehri Dam has been the object of protests. Environment activist Shri Sunder Lal Bahuguna led the "Anti Tehri Dam Movement" from 1980s to 2014. The protest was against the displacement of town inhabitants and environmental consequences of the weak ecosystem. The relocation of more than 1,00,000 people from the area has led to protracted legal battles over resettlement rights and ultimately resulted in the delayed completion of the project.

(a) How is hydropower harnessed?

(b) Define 1 MW.

(c) Mention two disadvantages of constructing Tehri Dam.

(d) What happens when water from great heights is made to fall on blades of turbine?