101. Permanent hardness of water can be removed by adding September 20, 2025 by Admin A. chlorine B. washing soda C. potassium permanganate D. bleaching powder ✅ The correct answer is option B.
102. Air is a/an September 20, 2025 by Admin A. compound B. element C. electrolyte D. mixture ✅ The correct answer is option D.
103. Production of chlorofluorocarbons (CFC) gas which is proposed to be banned in India, is used in which of the following domestic products? September 20, 2025 by Admin A. Television B. Refrigerator C. Tube light D. Cooking gas ✅ The correct answer is option B.
104. Chemical formula for water is September 20, 2025 by Admin 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 September 20, 2025 by Admin 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? September 20, 2025 by Admin 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? September 20, 2025 by Admin A. Krypton B. Xenon C. Neon D. Helium ✅ The correct answer is option D.
108. Non stick cooking utensils are coated with September 20, 2025 by Admin A. Teflon B. PVC C. black paint D. polystyrene ✅ The correct answer is option A.