Questions

A team of scientists led by Abhay Mudholkar, from CSIR-National Institute of Oceanography (CSIR-NIO) in Goa on February 17, 2017 informed that India’s only live volcano, the barren island volcano in the Andaman and Nicobar Islands has started erupting smoke and lava again. The Barren Island volcano last erupted in 1991 after lying dormant for 150 years. Again the volcano has started showing sporadic activity in small intervals of 5-10 minutes. As per the scientists, during the day only ash clouds were observed, but after sunset red lava foundations were erupting from the crater into the atmosphere and hot lava streamed down the slopes.

The logic in the given puzzle is 

Addition of numeric values of corresponding letters in the first three figures gives respective corresponding letter in fourth figure. 

i.e, A = 1 , W = 23 , B = 2 => 2 + 1 + 23 =26 = 'Z'

Similarly, L = 12, K = 11 , A = 1 => 1 + 11 + 12 = 24 = 'X'

Here the missing letter is 'X'.

A ridge ine is a line formed along the highest points of a mountain ridge.

Irrigation canals are generally aligned along ridge lines.

The Gandhi Sagar Dam is built on Chambal river and is located in the Mandsaur & Neemuch district of Madhya Pradesh.

The dam’s reservoir area is the second-largest in India (after the Hirakud Reservoir), and attracts a large number of migratory and non-migratory birds throughout the year.

It is a masonry gravity dam, standing 62.17 metres (204.0 ft) high.