The most important raw material used in the manufacture of cement are
(A) Potassium nitrate, charcoal and sulphur
(B) Limestone, clay and gypsum
(C) Transition metal oxides, sodium hydroxide or potassium hydroxide
(D) Limestone, sodium carbonate and silica
Consider the following statements :
1. Diamond is hard and graphite is soft.
2. diamond is soft and graphite is hard.
3. Diamond is a bad conductor but graphite is a good conductor.
4. Diamond is a good conductor but graphite is a bad conductor.
Which of the statements given above is/are correct ?
(A) 1 and 3 (B) 1 only
(C) 2 and 3 (D) 1 and 4
Which one among the following transitions is associated with the largest change in energy in hydrogen atom
(A) n = 5 to n = 3 (B) n = 2 to n = 1
(C) n = 3 to n = 2 (D) n = 4 to n = 2
An iron ball and a wooden ball of the same radius are released from a height 'H' in vacuum. The time taken to
reach the ground will be -
(A) more for the iron ball (B) more for the wooden ball
(C) equal for both (D) in the ratio of their weights