11) Brass is an alloy of:
(A) Copper and Tin
(B) Copper and Zinc
(C) Copper and Nickel
(D) Aluminum and Magnesium
12) Astronauts cannot talk to each other on the surface of the moon because
(A) Sound waves are absorbed
(B) Sound waves cannot travel through vacuum
(C) There are obstructions to the sound waves
(D) The temperature is high near the moon's surface
13) The mechanical advantage of a lever will be large if its
(A) Arms on opposite sides of the fulcrum are equal
(B) Arms are unequal one of them is shorter not being material
(C) Arm on the side of the load is longer than the other arm
(D) Arm on the side of the load is shorter than the other arm
14) What is the instrument that determines specific gravity of liquids?
(A) Hygrometer
(B) Hydrometer
(C) Gravimeter
(D) Hypsometer
15) Convex lenses are used for the correction of:
(A) Long-sightedness
(B) Short-sightedness
(C) Cataract
(D) None of these
16) A transformer is used to:
(A) Increase DC voltage
(B) Increase or decrease AC voltage
(C) Decrease DC voltage
(D) Convert DC into AC
17) The stones formed in human kidney consist mostly of:
(A) Calcium oxalate
(B) Sodium acetate
(C) Magnesium sulphate
(D) Calcium
18) Most of the explosions in mines occur due to the mixing of:
(A) Hydrogen with oxygen
(B) Oxygen with acetylene
(C) Methane with air
(D) Carbon dioxide with ethane
19) The blood glucose level is commonly expressed as:
(A) Millimeter of Hg
(B) Milligram per decilitre
(C) Parts per million
(D) Grammes per litre
20) Soft drinks such as colas contain significant quantities of:
(A) Caffeine
(B) Nicotine
(C) Tannin
(D) Renin