506: Which one of the following elements is alloyed with iron to produce steel which can resist high temperatures and also have high hardness and abrasion resistance ?
(a) Aluminium
(b) Chromium
(c) Nickel
(d) Tungsten
507: Who is regarded as the greatest lawgiver of ancient India?
(a) Megasthanese
(b) Panini
(c) Manu
(d) Kautilya
508: Out of all the Biosphere Reserves in India, four have recognized on the World Network by UNESCO. Which one of the following is not one of them?
(a) Kanchejunga
(b) Gulf of Mannar
(c) Nanda Devi
(d) Sunderbans
509: Which one of the following countries has replaced Italy as the major importer of bauxite from India ?
(a) Canada
(b) Greece
(c) Ukraine
(d) United Arab Emirates
510: In an accurate clock, on a period of 2 hours 20 minutes, the minute hand will move over
(a) 520°
(b) 320°
(c) 840°
(d) 140°