18. Two lamps, one rated 100W at 220V and other 60W at 220V are connected in parallel to the electric supply at 220V. Draw a circuit diagram to show the connections. Calculate the total current drawn from the electric supply. 19.i) What is refining of a metal ? ii) Describe the electrolytic refining of copper metal with the help of a labelled diagram. iii) Mention constituent metals present in bronze. 20.a) You have four solutions A,B,C and D.The pH solution A is 6, B is 9 ,C is 12 and D is 7. Identify the most acidic and most basic solutions. ii)Arrange the four solutions in the increasing order of H+ ion concentration iii)State the change in colour of pH paper on dipping in solution Cand then D. Dry ammonia gas has no action on litmus but a solution of ammonia in water turns red litmus paper blue. Why is it so ? 21.a) Define electric power. b)How many joules are there in one kilowatt-hour? c) An electric heater draws current of 10A from a 220V supply.What is the cost of using heater for 5h everyday for 30 days, if the cost of one unit of electric energy is Rs 5.25? 22.a) Draw a neat labelled diagram of human digestive system. b) Differentiate between arteries and 23.a) Define reflex action. b)Draw a schematic diagram to depict reflex arc c) Differentiate between sensory and motor nerves. 24. a) What is the conversion of energy in electric generator? b)State the principle of working of generator. c) Why is it necessary to earth metallic appliances? SECTION : B (PBQ) 25.A student tested pH of the distilled water and found the colour changed to Green b) Red c)Blue d)Yellow 26.A small amount of quick lime is taken in a beaker. Water is added slowly to the beaker. a) Hissing sound and the solution becomes hot b) A hissing sound and the solution becomes cold c) Hissing sound and the solution becomes cold d) No sound and solution becomes hot
18. Two lamps, one rated 100W at 220V and other 60W at 220V are connected in parallel to the electric supply at 220V. Draw a circuit diagram to show the connections. Calculate the total current drawn from the electric supply. 19.i) What is refining of a metal ? ii) Describe the electrolytic refining of copper metal with the help of a labelled diagram. iii) Mention constituent metals present in bronze. 20.a) You have four solutions A,B,C and D.The pH solution A is 6, B is 9 ,C is 12 and D is 7. Identify the most acidic and most basic solutions. ii)Arrange the four solutions in the increasing order of H+ ion concentration iii)State the change in colour of pH paper on dipping in solution Cand then D. Dry ammonia gas has no action on litmus but a solution of ammonia in water turns red litmus paper blue. Why is it so ? 21.a) Define electric power. b)How many joules are there in one kilowatt-hour? c) An electric heater draws current of 10A from a 220V supply.What is the cost of using heater for 5h everyday for 30 days, if the cost of one unit of electric energy is Rs 5.25? 22.a) Draw a neat labelled diagram of human digestive system. b) Differentiate between arteries and 23.a) Define reflex action. b)Draw a schematic diagram to depict reflex arc c) Differentiate between sensory and motor nerves. 24. a) What is the conversion of energy in electric generator? b)State the principle of working of generator. c) Why is it necessary to earth metallic appliances? SECTION : B (PBQ) 25.A student tested pH of the distilled water and found the colour changed to Green b) Red c)Blue d)Yellow 26.A small amount of quick lime is taken in a beaker. Water is added slowly to the beaker. a) Hissing sound and the solution becomes hot b) A hissing sound and the solution becomes cold c) Hissing sound and the solution becomes cold d) No sound and solution becomes hot