❑ Choose the best choice in the following statements.

  1. Select the correct association:

(a) Oxidation – loss of an electron                          (b) Oxidation – gain of an electron

(c) Reduction – gain of a neutron                               (d) Reduction – loss of a neutron

  1. Radioactive isotope of Uranium used in Nuclear Bomb is

(a) 0422                              (b) 92U234                                                               (c) 92U233                          (d) 92U238

  1. Human population growth is greatest in developing countries because:
  • The birth rate is high in developing countries
  • The death rate is high in developing countries
  • Much of the population has already reached the puberty
  • Most of the worlds population lives in industrialized countries
  1. Which woody raw material is used for the manufacture of paper pulp?

(a) Cotton                           (b) Poplar                          (c) Bagasse                         (d) Rice straw

  1. Rectified spirit contains alcohol about:

(a) 80%                               (b) 95°A,                                                                 (c) 70%                               (d) 85%

  1. Which of the following elements is not present abundantly in earth’s crust?

(a) Silicon                          (b) Radium                       (c) Aluminium                 (d) Carbon

  1. The famous book Al-Qanoon was written by the Muslim scientist

(a) Jabar bin Hayyan                                                      (b) Zakariya Al-Razi

(c) Abu Ali Sina                                                             (d) Abdul Qasim Majreeti

  1. Basic metals can be converted into gold by:

(a) Heating                                                                         (b) Beating

(c) Artificial nuclear radioactivity                         (d) Chemical reaction

  1. A light year is a unit of:

(a) Time                               (b) Energy                          (c) Length                          (d) Mass

  1. One of the main functions of the earth’s ozone layer is to:

(a) Prevent global warming                                          (b) Filter out ultraviolet rays

(c) Absorb pollution                                                     (d) All of the above

U Name the following:

  • The alloy which consists of copper and tin. (Bronze)
  • The device used to measure radioactivity. (Geiger counter)
  • The organ in the human body which is responsible for the digestion of protein only. (Stomach)
  • The instrument used to measure very high temperature. (Pyrometer)
  • The scientist who designed the first internal combustion engine used to burn low grade fuel. (Jean J. Lenoir)
  • The scientist who asserted the earth to be a huge magnet. (William Gilbert)
  • The metal known as quick silver. (Mercury)
  • The device which converts the chemical energy into electrical energy. (Battery)
  • The first person to orbit the earth in space. (Yuri Gagarin)
  • The scientist who discovered water. (Henry Cavendish)
  • Which of the following statements are true and which are false:
  • To stay in the sunlight while circling the globe at the equator, one has to move with a speed of 1670 km/hour. (True)
  • Infrared waves have more wavelengths than the red colour. (True)
  • Liver produces bile which is involved in the breakdown of fats. (True)
  • A secondary cell can be charged again. (True)
  • Nucleic acids are responsible basically for protein synthesis in the human body. (True)
  • The quality of gasoline is checked by its octane number. (True)
  • Image in a plane mirror is not laterally inverted. (False)
  • Horse power is the unit of mechanical energy. (False)
  • Sound travels faster in vacuum than in water. (False)
  • Nitrogen is the most occurring element in the human body. (False)
  • Fill in the blanks:
  • The variation in the blood flow can be heard with an instrument called__ . (Stethoscope)
  • There is a place in the retina where the light sensitive cells are interrupted by the presence of the optic nerve head. It is known as . (Blind spot/ optic disc)
  • The study of human population is called___ . (Demography or population science)
  • Human beings belong to species are called_____ . (Sapien)
  • Defect of eye due to which nearly located objects are not clearly visible is called __________
  • About___ of the human body consists of water. (65-75%)
  • All of the oxygen that you breathe has been produced by the splitting of water during______
  • The important ore of Chromium is_____ . (Chromite)
  • acid was discovered by Jabbar bin Hayyan. (Sulphuric)
  • The measurement of rainfall is made by an instrument known as____ . (Rain gauge)