1 . Radiocarbon is produced in the atmosphere as a result of
A. lightning discharge in atmosphere
B. action of ultraviolet light from the sun on atmospheric oxygen
C. collision between fast neutrons and nitrogen nuclei present in the atmosphere
D. action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere

2 . It is easier to roll a stone up a sloping road than to lift it vertical upwards because
A. work done in rolling is more than in lifting
B. work done in lifting the stone is equal to rolling it
C. work done in rolling a stone is less than in lifting it
D. work done in both is same but the rate of doing work is less in rolling

3 . The absorption of ink by blotting paper involves
A. diffusion of ink through the blotting
B. capillary action phenomenon
C. viscosity of ink
D. siphon action

4 . Siphon will fail to work if
A. the level of the liquid in the two vessels are at the same height
B. the temperature of the liquids in the two vessels are the same
C. the densities of the liquid in the two vessels are equal
D. both its limbs are of unequal length

5 . Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to
A. hysteresis loss alone
B. intense sunlight at noon
C. the heating effect of current alone
D. both the heating effect of current and hysteresis loss