4476: The half-life of a radio active element is 5 years. The fraction of the radioactive substance that remains after 20 years is
(a) 1/2
(b) 1/4
(c) 1/8
(d) 1/16
4477: Which important event immediately preceded Jallianwala Bagh massacre?
(a) Rowlatt Act enactment
(b) Communal award
(c) Coming of Simon Commission
(d) Quit India Movement
4478: Prem Vatika, poems on the life of Krishna, was composed by
(a) Bihari
(b) Surdas
(c) Raskhan
(d) Kabir
4479: Who among the following is a Hindustani classical singer ?
(a) Geeta Chandran
(b) Gangubai Hangal
(c) Swapnasundari
(d) Leela Samson
4480: The January isotherm taken as a basis for dividing India into tropical and sub-tropical zones is
(a) 21°C
(b) 18°C
(c) 12°C
(d) 15°C