Which of the following is used for regulated electric supply? (1) Zener diode (2) Junction diode (3) Gun diode (4) Tunnel diode Answer: (1) The Zener diode is like a general-purpose signal diode. When based in the forward direction it behaves just like a normal signal diode, but when a reverse voltage is applied to it, … Read more
The source of the Sun’s energy is the process of (1) Photoelectric emission (2) Nuclear fission (3) Nuclear fusion (4) Thermionic emission Answer: (3) Nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or “fuse”, to form a single heavier nucleus. During this process, the matter is not conserved because … Read more
Gamma rays can cause (1) genemutation (2) sneezing (3) burning (4) fever Answer: (1) In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell’s genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes … Read more
The substance which conducts current in the solid-state is (1) diamond (2) graphite (3) iodine (4) sodium chloride Answer: (2) The structure of graphite is unlike most other network substances. It is formed in ‘sheets’ of carbon atoms, each of which is bonded to only three others. The fourth valence electron of the carbon atom is … Read more
Which set of conditions represents the easiest way to liquify a gas? (1) Low temperature and high pressure (2) High temperature and low pressure (3) Low temperature and low pressure (4) High temperature and high pressure Answer: (1) Low temperature and high-pressure set of conditions represent the easiest way to liquefy a gas. Liquefaction of gases … Read more
What is the colour of light related to? (1) Amplitude (2) Frequency (3) Quality (4) Velocity Answer: (1) Colour or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue, and others. Colour derives from the spectrum of light (distribution of light power versus wavelength) interacting in the eye with … Read more
What principle/law explains the working of the hydraulic brakes in automobiles? (1) Bernoulli’s law (2) Posieulle’s principle (3) Pascal’s law (4) Archimedes’ principle Answer: (3) Hydraulic brakes work on the principle of Pascal’s law which states that “pressure at a point in a fluid is equal in all directions in space”. According to this law when … 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
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
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