Questions

The thinnest layer is crust. It is about 100km. Where as mantle ranges upto 2900 km and the inner most core ranges upto 6300km.

1) Former President - Pranab Mukherjee

2) Social activist Late - Nanaji Deshmukh

3) Singer Late - Bhupen Hazarika

were confirmed with the India's highest civilian honour Bharat Ratna for 2018.

The meanings of the given words are as follows:
Zealous: having or showing zeal
Droopy: hanging down limply
Gigantic: of very great size or extent; huge or enormous
Tenacity: the quality or fact of being able to grip something firmly; grip
Assiduity: constant or close attention to what one is doing
Fervent: having or displaying a passionate intensity
Apathetic: showing or feeling no interest, enthusiasm, or concern
Conceited: excessively proud of oneself; vain
Capacious: having a lot of space inside; roomy
Hilarity: extreme amusement, especiallywhen expressed by laughter
Livid: furiously angry
Therefore, it can be observed that option C i.e. ‘fervent, apathetic’ forms a synonym- antonym pair of ‘zealous’.

A.R. Rahman making the anthem for upcoming Hockey World Cup 2018's prime video.

Kepler’s  laws  of  planetary  motion state  that  (a)  All  planets  move  in elliptical orbits with the Sun at one of  the  focal  points  (b)  The  radius vector  drawn  from  the  sun  to  a planet  sweeps  out  equal  areas  in equal  time  intervals.  This  follows from  the  fact  that  the  force  of gravitation on the planet is central and  hence  angular  momentum  is conserved.  (c)  The  square  of  the orbital   period   of   a   planet   is proportional  to  the  cube  of  the semi  major  axis  of  the  elliptical orbit of the plane.