666: Khetri, Kolar, Sindri and Jharia are associated with:
(a) Copper, gold, fertilisers and coal
(b) Copper, gold, coal and iron
(c) Copper, gold, coal and gypsum
(d) Iron, gold, coal and copper
667: 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
668: Assertion (A):
During the Neap Tides, the high tide is lower and the low tide is higher than usual.
Reason (R):
The Neap Tide, unlike the Spring Tide, occurs on the New Moon instead of on the Full Moon.
(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 a correct explanation of A
(c) A is true, but R is false
(d) A is fasle, but R is true
669: The Barrah dacoity was the first major venture of the revolutionary terrorist of the freedom movement in
(a) Bombay-Karnataka
(b) Punjab
(c) East Bengal
(d) The Madras Presidency
670: In a class there are 18 boys who are over 160 cm tall. If these boys constitute three-fourths of the boys and the total number of boys is two-third of the number of students in the class, then what is the number of girls in the class?
(a) 6
(b) 12
(c) 18
(d) 24