41. Battery contains many electrical cells joined together, for example, in torches and portable radios, dry cells are used. What cells does a car battery contain?
(a) Lead-zinc cells
(b) Lead-acid cells or lead accumulators
(c) Brass-acid or lead accumulators
(d) Bronze-acid or lead accumulators
42. What is known as the temperature at which a liquid turns into a vapor or gas?
(a) Boiling point
(b) Vapour point
(c) Gas point
(d) End point
43. What is called the temperature at which a liquid changes to a solid?
(a) Freezing point
(b) Solid point
(c) Changing point
(d) End point
44. Calcium (Ca) is a silvery white metal that reacts easily with many other elements. Calcium carbonate occurs as chalk, limestone, and marble. Where is calcium phosphate used?
(a) In cement
(b) In paper making
(c) In fertilizers
(d) In welding
45. Calcium sulfate is found as gypsum and anhydrite, and blackboard chalk is made of calcium sulfate. What effect do calcium compounds have in water?
(a) Cause evaporation
(b) Cause salinity
(c) Cause heaviness
(d) Cause hardness of water
46. Name any group of chemical compounds which contains carbon, hydrogen, and oxygen only, with a ratio of hydrogen to oxygen atoms usually 2:1?
(a) Hydrocarbon
(b) Carbohydrate
(c) Hydrates
(d) Organic Compounds
47. Which is the most important element because it is found in all living matters and occurs naturally in the form of diamond and graphite?
(a) Oxygen
(b) Carbon
(c) Hydrogen
(d) Lead
48. What material, commonly used for car engine blocks, is cheap but invaluable in construction?
(a) Cast Iron
(b) Stainless steel
(c) Steel
(d) Hard Iron
49. Centrifugal and centripetal forces act on a body as it moves along a:
(a) Curved path
(b) Straight path
(c) Angular path
(d) None of these
50. What are objects made from clay and hardened into a permanent form by baking (firing) at very high temperatures in a kiln called?
(a) Pot
(b) Brick
(c) Glassware
(d) Ceramics