101. Permanent hardness of water can be removed by adding
A. chlorine
B. washing soda
C. potassium permanganate
D. bleaching powder
✅ The correct answer is option B.
General Science MCQs
103. Production of chlorofluorocarbons (CFC) gas which is proposed to be banned in India, is used in which of the following domestic products?
A. Television
B. Refrigerator
C. Tube light
D. Cooking gas
✅ The correct answer is option B.
104. Chemical formula for water is
A. NaAlO2
B. H2O
C. Al2O3
D. CaSiO3
✅ The correct answer is option B.
105. The two elements that are frequently used for making transistors are
A. boron and aluminium
B. silicon and germanium
C. iridium and tungsten
D. niobium and columbium
✅ The correct answer is option B.
106. Which of the following metals remain in liquid for under normal conditions?
A. Radium
B. Zinc
C. Uranium
D. Mercury
✅ The correct answer is option D.
107. Which of the following was to be discovered first in the chromospheres of the sun?
A. Krypton
B. Xenon
C. Neon
D. Helium
✅ The correct answer is option D.
108. Non stick cooking utensils are coated with
A. Teflon
B. PVC
C. black paint
D. polystyrene
✅ The correct answer is option A.