CBSE ADDA

CBSE ADDA 1. The type of glass used in making lenses and prisms is? (a) soft glass (b) pyrex glass (c)jena glass (d) flint glass 2. Wood is the main raw material for the manufacture of ? (a) paint (b) paper (c) ink (d) gun powder 3. How does common salt help in separating soap from the solution after saponification? (a) By decreasing solubility of soap (b) By increasing solubility of soap (c) By decreasing density of soap (d) By increasing density of soap 4. Which of the following is commonly called a ‘polyamide’? (a) Rayon (b) orlon (c)Terylene (d) Nylon 5. The major ingredient of leather is ? (a)carbohydrate (b) collagen (c)polymer (d) nucleic acid 6. In the manufacture of safety matches, which of the following materials are used to coat the two sides of match boxes? 1. Yellow phosphorus 2. Glue 3, Glass powder 4. Red phosphorus (a) l, 2 and 3 (b) l,3 and 4 (c) l,2 and 4 (d) 2,3and4 7. Glass is made of the mixture of ? (a)quartz and mica (b) sand and s

Which instrument is used to measure pressure? Saccharimeter Ammeter Manometer Lactometer What does Angstrom measure? Quantity of liquid Length of light waves Length of cables Speed of ships Light year is related to Energy Speed Distance Intensity Match the following columns Column 1 Column 2 A. Relative 1. Pyrometer humidity B. Anemometer 2. High temperature C. Navigation 3. Hygrometer D. Direction of wind 4. Chronometer 1 2 3 4 a. B D A C b. D B A C c. A D B C d. C A D B Which of the following instruments is used to measure pressure of gases? Barometer Manometer Ammeter None of these Joule is the unit of Temperature pressure Energy Heat How many Dynes are there in one gram weight? 900 375 981 250 How many Ergs are these in 1 Joule? 102 104 106 107 The unit of current is Ohm Watt Ampere None of these The unit of energy in MKS system is Volt Erg Ohm Joule The intensity of an earthquake is measured with a Barometer Hydrometer

1. Which of the following is not an ore of Aluminium? (A) Felsper (B) Bauxite (C) Cryolite (D) Azurite 2. Most soluble in water is — (A) Camphor (B) Sugar (C) Sulphur (D) Common Salt 3. Bromine is — (A) colourless gas insoluble in water (B) A highly inflammable gas (C) A Black solid. (D) A red liquid. 4. The metal used in storage batteries — (A) Iron (B) Copper (C) Lead (D) Zinc 5. Water has maximum density at — (A) –4°C (B) 0°C (C) 4°C (D) 100°C 6. The chemial name of Uria is — (A) Aneurin (B) Chloroetane (C) Carbamide (D) None of these 7. Permanent hardness of water can be removed by adding — (A) Potassium Permanganate (B) Chlorine (C) Bleaching Powder (D) Washing Soda 8. The formula of Plaster of Paris is — (A) CaSO 4 (B) CaSO 4 , 2H 2 O (C) 2CaSO 4 , 4H 2 O (D) 2CaSO 4 , H 2 O 9. Which of the following substance is a bad conductor of electricity but a good conductor of heat? (A) Asbestos (B) Celluloid (C) Purspecks (D) Mica 10. Carborandum is — (A) Silicon Dioxide (B) Silicon Carbi

1. Which of the following is the lightest metal ? (A) Mercury (B) Silver (C) Lithium (D) Lead 2. The most important ore of Aluminium is — (A) Bauxite (B) Calamine (C) Calcite (D) Galena 3. The element present in the largest amount in rocks and minerals is — (A) Carbon (B) Silicon (C) Hydrogen (D) Aluminium 4. An alloy used in making heating elements for electric heating devices is — (A) Solder (B) Alloysteel (C) Nichrome (D) German Silver 5. German Silver is an alloy of — (A) Copper, Silver & Nickel (B) Silver, Copper & Aluminium (C) Zinc, Copper & Nickel (D) Silver, Zinc & Nickel 6. Air is a/an — (A) Compound (B) Element (C) Mixture (D) Electrolyte 7. Which of the following is the best conductor of Electricity ? (A) Ordinary water (B) Sea water (C) Boiled water (D) Distilled water 8. Balloons are filled with — (A) Helium (B) Oxygen (C) Nitrogen (D) Argon 9. The charcoal used to decolourise raw sugar is — (A) Animal charcoal (B) Sugar charcoal (C) Cocoanut charcoal (D)

1.  Brass gets discoloured in air because of the presence of which of the following gases in air? A. Oxygen B. Hydrogen sulphide C. Carbon dioxide D. Nitrogen                Answer:  Option  B 2.  Which of the following is a non metal that remains liquid at room temperature? A. Phosphorous B. Bromine C. Chlorine D. Helium            Answer:  Option  B   3.  Chlorophyll is a naturally occurring chelate compound in which central metal is A. copper B. magnesium C. iron D. calcium  Answer:  Option  B 4.  Which of the following is used in pencils? A. Graphite B. Silicon C. Charcoal D. Phosphorous          Answer:  Option  A 5.  Which of the following metals forms an amalgam with other metals? A. Tin B. Mercury C. Lead D. Zinc         Answer:  Option  B 6.  Chemical formula for water is A. NaA1O 2 B. H 2 O C. Al 2 O 3 D. CaSiO 3 7.  The gas usually filled in the electric bulb is A. nitrogen B. hydrogen C. carbon dioxide D. oxygen         An