3739. Mass of a positron is same as that of a/an
electron
α-particle
proton
neutron
✅ The correct answer is option A.
3743. Graphite is used in nuclear reactor as
insulation lining of the reactor.
fuel.
lubricant.
retarder of neutron velocity.
✅ The correct answer is option D.
3715. Safety rods provided in nuclear reactors to guard against accidents, in case of earthquake are made of
high carbon steel.
molybdenum.
zircalloy.
boron or cadmium.
✅ The correct answer is option D.
3724. Ceramic nuclear metals compared to solid nuclear metals have
higher melting points.
low strength at high temperature.
more chances of radiation damage.
poorer corrosion resistance.
✅ The correct answer is option A.
3683. Excessive use of chemical fertilisers causes shrivelling of the roots and wilting of the plant, because the
Osmotic pressure of the soil water becomes less than that of the plant sap
Soil becomes too alkaline
Osmotic pressure of the soil water becomes higher than that of the plant sap
Soil becomes too acidic
✅ The correct answer is option C.
3688. Urea is a better fertilizer than ammonium sulphate, because
It is cheaper
Nitrogen content is higher
It is not poisonous
It is easy to manufacture
✅ The correct answer is option B.
3693. During conversion of ammonium carbamate into urea, presence of large excess of water
Increases the yield of urea
Adversely affects the yield of urea
Reduces the evaporator load by diluting the urea solution
Does not affect the yield of urea
✅ The correct answer is option B.
3698. Steam reforming of naphtha is a source of hydrogen production for nitrogeneous fertiliser industry. What is the usual ratio of steam to carbon maintained in the process of steam reforming of naphtha?
1.5:1
3.5:1
10:01
15:01
✅ The correct answer is option B.
3704. Which nutrient in fertiliser makes the plant stems stronger and increases branching?
Nitrogen
Phosphorous
Potassium
Calcium
✅ The correct answer is option B.