CBSE ADDA

MCQ Sample Question Paper  X  Based On Practical skill 1. When we start heating a mixture of sulphur powder and iron fillings, we would observe  that (a) Surphur starts melting.                   (b) Iron filings start melting. (c) Mixture becomes red hot.  (d) mixture evaporates Ans (a) Sulphur has a lower melting point than iron. 2 A student added 2 drops of iodine solution into 4 ml of starch solution in test tube  A, another student added 2 ml of starch solution into 4 ml of iodine solution in test tube B. They would then observe (a) a change of colour to blue black in test tube A but not in test tube B. (b) a change of colour to blue black in test tube B but not in test tube A. (c) a change of colour to blue black in both test tubes A and B (d) no change of colour in any test tube. Ans

Set-1Practical Skills in Science 1. The two colours seen at the extreme ends of the pH chart are (a) red and blue.  (b) red and green. (c) green and blue. (d) orange and green Ans: (a) Red colour is at the top and blue colour is at the bottom. 2. A student observed that the colour of pH paper changes to green when shedipped it in water. She added a few drops of concentrated hydrochloric acid to the water. The colour of pH paper would turn to (a) light red.  (b) apple green. (c) dark blue. (d) lemon yellow. Ans: (a) The colour of pH paper is green in neutral medium, whereas it is red in acidic medium. 3. When zinc reacts with dilute hydrochloric acid (a) the surface of zinc becomes brighter.   (b) the surface of zinc becomes black and dull. (c) the metal turns into powder.                  (d) the reaction mixture turns green. Ans: (b)  The surface becomes black and dull as the reaction proceeds 4. Students A, B and C were given five raisins each of equal weight. The raisins  were soa