Questions

Photography is a word derived from Greek words Photo means light and graphe means drawing.'Hence it literally means light drawing.

The comma ( , ) is a punctuation mark in English which is most frequently used.

It is perhaps also the most abused and misused punctuation mark among all.

A relationship.

1) G.V. Mavalankar (1952-56)

2) M.A. Ayyangar (1956-57 & 1957-62)

3) Hukam Singh (1962-67)

4) N. Sanjiva Reddy (1967-69)

5) Gurdial Singh Dhillon (1969-1971 & 1971-1975)

6) Bali Ram Bhagat (19976-77)

7) K.S. Hegde (1977-80)

8) Balram Jakhar (1980-1984 & 1984-1989)

9) Rabi Ray (1989-91)

10) Shivraj Patil (1991-96)

11) P.A. Sangma (1996-98)

12) G.M.C. Balayogi (1998-99 & 1999-2002)

 13) Manohar Joshi (2002-04)

14) Somnath Chatterjee (2004-09)

15) Meira Kumar (2009-14)

16) Sumitra Mahajan (2014-19)

17) Om Birla (2019 -)

Based on conventionality in deriving energy, energy sources could be classified as

Conventional ::

coal, oil, hydro, nuclear, etc... sources which can be used up or exhaustible.

(and)

Non - conventional ::

solar, wind, tidal, geothermal, biogas, etc... sources which are not exhausted.

Among the given options, Geothermal energy is the alternative energy source among all the choices that are given in the question, that is exhaustible.

Covalent bonds hold atoms together because the attraction between the positively charged nuclei and the negatively charged shared electrons is greater than the repulsions between the nuclei themselves.