Speed of sound is the greatest in : (1) Water (2) Air (3) Glass (4) Glycerine Answer: (3) Sound travels faster in liquids and non-porous solids than it does in air. It travels about 4.3 times as fast in water (1,484 m/s), and nearly 15 times as fast in iron (5,120 m/s), than in air at … Read more
The instrument which uses sound waves to measure the depth of oceans is (1) Radar (2) Sonar (3) Altimeter (4) Venturimeter Answer: (2) The instrument which uses sound waves to measure the depth of oceans is sonar. Sound waves can travel much faster from one point to another. Sound waves are far more accurate for measuring … Read more
Clear nights are colder than cloudy nights because of (1) conduction (2) condensation (3) radiation (4) insolation Answer: (3) Cloudless nights are colder because the nights that have clouds provide a blanket for the earth and trap some of the hot day air whereas the cloudless nights have no protection so all the hot air rises … Read more
What apparatus is used to locate a submerged object? (1) Radar (2) Sonar (3) Quasar (4) Pulsar Answer: (2) Sonar (originally an acronym for Sound Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, … Read more
When a bottle of scent is kept open in a corner of a room its odour is felt in all parts of the room. This is due to the phenomenon of : (1) evaporation (2) vaporisation (3) diffusion (4) sublimation Answer: (3) Diffusion is one of several transport phenomena that occur in nature. A distinguishing feature … Read more
What is viewed through an electron microscope? (1) Electrons and other elementary particles (2) Structure of bacteria and viruses (3) Inside of human stomach (4) Inside of the human eye Answer: (2) Electron microscopes are used to observe a wide range of biological and inorganic specimens including microorganisms, cells, large molecules, biopsy samples, metals, and crystals. … Read more
The Electron microscope was invented by (1) Knoll and Ruska (2) Robert Koch (3) Leeuwenhoek (4) C.P. Swanson Answer: (1) It is widely accepted that the first prototype of an electron microscope was built by Ernst Ruska and Max Knoll in 1931; it was not more powerful than an optical microscope, but it demonstrated the principle … Read more
The best conductor of heat among the following is (1) alcohol (2) mercury (3) ether (4) water Answer: (2) Since mercury is 13+ times as dense as water, a given volume of mercury would carry about 4.4 times as much heat, so mercury is the best conductor of heat among the given options. It is the … Read more
Solar energy is converted into chemical energy during (1) Transpiration (2) Photosynthesis (3) Diffusion (4) Osmosis Answer: (2) In photosynthesis, solar energy is converted to chemical energy. The chemical energy is stored in the form of glucose (sugar). Carbon dioxide, water, and sunlight are used to produce glucose, oxygen, and water. Photosynthesis is a process used … Read more
A particle dropped from the top of a tower uniformly falls on the ground at a distance that is equal to the height of the tower. Which of the following paths will be traversed by the particle? (1) Circle (2) Parabolic (3) Great circle (4) Hyper–parabolic Answer: (2) If a particle dropped from the top of … Read more