21: Water which contains soluble salts of calcium and magnesium is known as
(a) Heavy water
(b) Soft water
(c) Hard water
(d) Mineral water
22: Match List I with List II and select the correct answer by using the codes given below the lists :
List I List II
(Special Characteristic) (Name of Planet)
I. Farthest planet from the sun ------------ (A) Mercury
II. Largest planet of the solar system ---- (B) Venus
III. Planet second from the Sun in the solar system ------------ (C) Jupiter
IV. Planet nearest to the Sun -------------- (D) Pluto
------------------------------------- (E) Saturn
Codes:
(a) I-B, II-C, III-E, IV-A
(b) I-C, II-E, III-A, IV-B
(c) I-D, II-A, III-B, IV-C
(d) I-D, II-C, III-B, IV-A
23: Assertion (A) :
The temperature of a metal wire rises when an electric current is passed through it.
Reason (R):
Collision of metal atoms with each other releases heat energy.
(a) Both A and R are true, and R is the correct explanation of A
(b) Both A and R are true, but R is NOT a correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true
24: Dilip Kaur Tiwana is well known as a
(a) litterateur
(b) musician
(c) scientist
(d) sports person
25: Which one of the following was the first fort constructed by the British in India ?
(a) Fort William
(b) Fort St. Angelo
(c) Fort St. David
(d) Fort St. George