51: Cryogenic engines find applications in
(a) sub-marine propulsion
(b) frost-free refrigerators
(c) rocket technology
(d) researches in superconductivity
52: Which of the following can be threats to the biodiversity of a geographical area?
1. Global warming
2. Fragmentation of habitat
3. Invasion of alien species
4. Promotion of vegetarianism
Select the correct answer using the codes given below :
(a) 1, 2 and 3 only
(b) 2 and 3 only
(c) 1 and 4 only
(d) 1, 2, 3 and 4
53: Assertion (A): Muhammad bin Tughlaq issued a new gold coin which was called Dinar by Ibn Batutah.
Reason (R) : Muhammad bin Tughlaq wanted to issue token currency in gold coins to Promote trade with West Asian and North African countries.
(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
54: Recommended daily intake of proteins for a moderately active woman is
(a) 30 g
(b) 37 g
(c) 40 g
(d) 46 g
55: Which of the following is correct for tea?
(a) Alkaline and nicotine
(b) Alkaline and caffeine
(c) Acidic and nicotine
(d) Acidic and caffeine