1) Radiocarbon is produced in the atmosphere as a result of
collision between fast neutrons and nitrogen nuclei present in the atmosphere![]()
action of ultraviolet light from the sun on atmospheric oxygen![]()
action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere![]()
lightning discharge in atmosphere![]()
Answer : A Discuss
2) It is easier to roll a stone up a sloping road than to lift it vertical upwards because
work done in rolling is more than in lifting![]()
work done in lifting the stone is equal to rolling it![]()
work done in both is same but the rate of doing work is less in rolling![]()
work done in rolling a stone is less than in lifting it![]()
Answer : D Discuss
3) The absorption of ink by blotting paper involves
viscosity of ink![]()
capillary action phenomenon![]()
diffusion of ink through the blotting![]()
siphon action![]()
Answer : B Discuss
4) Siphon will fail to work if
the densities of the liquid in the two vessels are equal![]()
the level of the liquid in the two vessels are at the same height![]()
both its limbs are of unequal length![]()
the temperature of the liquids in the two vessels are the same![]()
Answer : B Discuss
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
the heating effect of current alone![]()
hysteresis loss alone![]()
both the heating effect of current and hysteresis loss![]()
intense sunlight at noon![]()
Answer : C Discuss
6) Nuclear sizes are expressed in a unit named
7) Light year is a unit of
8) Mirage is due to
unequal heating of different parts of the atmosphere![]()
magnetic disturbances in the atmosphere![]()
depletion of ozone layer in the atmosphere![]()
equal heating of different parts of the atmosphere![]()
Answer : A Discuss
9) Light from the Sun reaches us in nearly
10) Stars appears to move from east to west because
all stars move from east to west![]()
the earth rotates from west to east![]()
the earth rotates from east to west![]()
the background of the stars moves from west to east![]()
Answer : B Discuss