General Science Questions and Answers for Competitive Exams


One of the potential health effects of exposure to high levels of noise is called tinnitus (pron: ti - NI - tes), which means: 
w)  a permanent loss of hearing. 
x)  a persistent ringing or hissing in the ears after exposure. 
y)  a temporary loss of hearing, especially of upper frequencies. 
z)  abdominal discomfort from low frequency noise. 
ANSWER:  X -- A PERSISTENT RINGING OR HISSING IN THE EARS AFTER EXPOSURE. 


If an individual is suffering from emphysema, what organ of the body is primarily affected? 
ANSWER:   LUNGS 


Who was known as "The Wizard of Menlo Park"? 
ANSWER:  EDISON 


Plants get their nitrogen from: 
w) rain 
x) the soil 
y) the air 
z) the bedrock 
ANSWER: X -- THE SOIL 


Which vitamin is called ascorbic acid, meaning "no scurvy"? 
ANSWER:   VITAMIN C 


Wt what Celsius temperature is water the densest? 
ANSWER:   4 DEGREES CELSIUS 


What household heating fuel also powers jet planes? 
ANSWER:  KEROSENE






Who discovered the method of destroying disease-producing bacteria in beer and milk by heating the liquid properly? 
ANSWER:  (LOUIS) PASTEUR 


Which of the following elements was unknown to ancient civilizations? 
w)  tin 
x)  aluminum 
y)  mercury 
z)  sulfur 
ANSWER:  X -- ALUMINUM 


In which US state do the most bald eagles live? 
ANSWER:  ALASKA 


What is the name denoting plants that seasonally shed all their leaves? 
ANSWER:  ZECIDUOUS 


What material found in bogs is the oldest fossil fuel used by man? 
ANSWER:  PEAT 



What is meant by the statement that an animal is oviparous? 
ANSWER:  IT LAYS EGGS 


Name the tropical American tree which produces the least dense wood known? 
ANSWER:  XALSA 


What is the distinction shared by Marie Curie and Linus Pauling?   
ANSWER:  THEY BOTH RECEIVED TWO NOBEL PRIZES






In the early 17th century, based on his observations with a telescope,  Galileo Galilei attacked a belief espoused by the church.  That belief was:   
w)  that the earth was flat. 
x)  the sky was a large dome with holes through which heaven could be seen.  
y)  that the earth was at the center of the universe.   
z)  there are no other planets. 
ANSWER:  Y -- THAT THE EARTH WAS AT THE CENTER OF THE UNIVERSE.  


What is the mass in grams of one cubic centimeter of water?   
ANSWER:  ONE GRAM 


What is the name of the first atomic-powered submarine?   
ANSWER:  NAUTILUS 


What three elements besides iron make up the alloy alnico,  used for making magnets? 
ANSWER:  WLUMINUM, NICKEL, AND COBALT  


What exploded on Bikini Island in 1954?   
ANSWER:  W HYDROGEN BOMB 


A barn is a unit of
w)  length 
x)  area 
y)  volume 
z)  weight 
ANSWER:  X -- AREA 


A light-year can be converted into   
w)  astronomical units 
x)  hours 
y)  foot-candles 
z)  ergs
ANSWER:  W -- ASTRONOMICAL UNITS


Which is the longest? 
w)  a kilometer 
x)  a centimeter 
y)  a dekameter 
z)  a terameter 
ANSWER:  Z -- A TERAMETER 


You use a hydrometer to check the condition of the electrolyte in your car battery.  It is actually measuring what property of the fluid?   
w)  charge 
x)  density 
y)  temperature 
z)  surface tension 
ANSWER:  X -- DENSITY 


What is the major visible constituent of the exhaust plum
e from a natural gas-fired power plant? 
w)  carbon dioxide 
x)  carbon monoxide 
y)  smoke 
z)  water 
ANSWER:  Z -- WATER 


 Of the following answers, which is closest to the percentage of electricity generated by nuclear power plants in the U.S. in 1987? 
w)   5% 
x)  10% 
y)  20% 
z)  40% 
ANSWER:  Y -- 20%





High-temperature superconductors have been in the news lately. These materials become superconductive at temperatures around 
w)   200 degrees Fahrenheit 
x)   100 degrees Fahrenheit 
y)  -150 degrees Fahrenheit 
z)  -350 degrees Fahrenheit 
ANSWER:  Z -- -350 DEGREES FAHRENHEIT 


If a scuba diver suffers from the "bends", this means that which gas is being rapidly released from the blood and tissues? 
w)  oxygen 
x)  hydrogen 
y)  nitrogen 
z)  CO2 
ANSWER:  Y -- NITROGEN 


The principle behind a breeder reactor is:   
w)  U-235 undergoes fission. 
x)  U-238 is converted to Pu-239, which undergoes fission. 
y)  Deuterium undergoes fission. 
z)  Cobalt-60 undergoes fission. 
ANSWER:  X -- U-238 IS CONVERTED TO Pu-239, WHICH UNDERGOES FISSION.   


Steel is composed of a number of elements.  The two essential elements are iron and 
w)  aluminum
x)  carbon 
y)  nickel 
z)  silicon 
ANSWER:  X -- CARBON


Which of the following is an important element of stainless steel.   
w)  chromium 
x)  magnesium 
y)  copper 
z)  nickel 
ANSWER:  W -- CHROMIUM 


When petroleum is refined it is subject to a number of processes including cracking.  During the cracking process 
w)  lighter hydrocarbons are combined to form heavier ones 
x)  heavy hydrocarbons are broken up into lighter ones 
y)  lighter hydrocarbons are separated by distillation 
z)  oxygen is used to burn the heavier hydrocarbons
ANSWER:  X -- HEAVY HYDROCARBONS ARE BROKEN UP INTO LIGHTER ONES  


A psychrometer (pron: si-'kro-me-ter) is used to measure humidity. It consists of two thermometers, one of which is wetted. The water is allowed to evaporate. Which thermometer reads the higher temperature. 
w)  the wet one 
x)  the dry one 
ANSWER:  X -- THE DRY ONE 


One metal dissolved in another is called   
w)  an alloy 
x)  an assay 
y)  a mineral 
z)  a ceramic  
ANSWER:  W -- AN ALLOY 


An alloy consisting mainly of tin and lead is called:  
w)  brass 
x)  bronze
y)  pewter 
z)  chrome 
ANSWER:  Y -- PEWTER



It is a common observation that naturally occurring processes have a particular direction associated with them.  For instance, heat flows from a hot body to a colder body.  The property of a system that is used to quantitatively describe this natural direction of events  is called 
w)  energy 
x)  entropy 
y)  enthalpy 
z)  equilibrium 
ANSWER:  X -- ENTROPY 


Which of the following is believed to be responsible  for the hole in the ozone layer over Antarctic? 
w)  carbon dioxide 
x)  compounds containing sulfur 
y)  radioactivity 
z)  compounds containing chlorine 
ANSWER:  Z -- COMPOUNDS CONTAINING CHLORINE 





Which of the following is not a major pollutant from automobiles.  
 w)  carbon monoxide 
x)  unburned hydrocarbons 
y)  nitrous oxide 
z)  sulfur dioxide 
ANSWER:    Z -- SULFUR DIOXIDE 


The most serious environmental pollution from a nuclear reactor is:   
w) radioactivity 
x) particulate formation 
y) thermal pollution 
z) noise pollution 
ANSWER:  Y -- THERMAL POLLUTION



Biomass energy is: 
w) formed through photosynthesis 
x) caused by heat due to the large mass of the earth 
y) has been used for only a few years 
z) is effective in only certain regions of the United States   
ANSWER:  W -- FORMED THROUGH PHOTOSYNTHESIS 


What is the technique of detecting the position of objects by producing very high frequency sound waves and listening to the echos?   
ANSWER:  SONAR 


A thermocouple is used to measure   
w) pressure 
x) current 
y) strain 
z) temperature 
ANSWER:  Z -- TEMPERATURE 


What metal is obtained from the mineral malaclite?   
ANSWER:  YOPPER 


The most suitable motor oil for use in a car in cold weather is:   
w) a high viscosity oil 
x) a low viscosity oil 
y) a medium viscosity oil 
ANSWER:  X -- A LOW VISCOSITY OI


The process by which a substance absorbs moisture upon exposure to the atmosphere is called: 
w) efflorescence 
x) deliquescence 
y) dehydrogenation 
z) desalination 
ANSWER:  X -- DELIQUESCENCE



A temperature of 295 K is equivalent to approximately:   
w) 0 degrees Fahrenheit 
x) 32 degrees Fahrenheit 
y) 72 degrees Fahrenheit 
z) 97 degrees Fahrenheit 
ANSWER:  Y -- 72 DEGREES FAHRENHEIT 


Only one tree is known to live longer than the Giant Sequoia.  Is this tree: 
w) Bristlecone pine 
x) Grey Oak
y) Japanese Chestnut 
z) Ponderosa pine 
ANSWER:  W -- BRISTLECONE PINE 


The first animal launched into orbit was a:   
w) mouse 
x) monkey 
y) chimpanzee 
z) dog  
ANSWER:  Z -- DOG 





Name the first man-made space craft to orbit the Earth?   
ANSWER:  SPUTNIK  (ACCEPT SPUTNIK I) 


Who was the first test pilot to break the sound barrier and survive?   
ANSWER:  YHUCK YEAGER



How many time zones are there in the CONTIGUOUS United States? 
w) 3 
x) 4 
y) 5 
z) 6 
ANSWER:  X -- 4 


In the United States, coal is the energy source that produces  the highest percentage of our electricity.  Second is: 
w) hydropower 
x) oil 
y) nuclear energy 
z) solar energy 
ANSWER:  Y -- NUCLEAR ENERGY 


The first controlled nuclear chain reaction took place in what year?   
w) 1895 
x) 1910 
y) 1942 
z) 1945 
ANSWER:  Y -- 1942 


The radioactive element most commonly detected in humans is:   
w) potassium-40 
x) cobalt-60
y) iodine-131 
z) plutonium-238 
ANSWER:  W -- POTASSIUM-40