Basic concepts to be known about electrics

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•  In case of liquids , Ohms law is fully obeyed 
•  A wire carrying current is not charged because the current in a wire is due to drifting of free electrons in a definite direction . But no. Of electrons in the wire at any instant is equal to the no. Of protons . Hence , the net charge on the wire is zero.
•  Alloys of constantan and maintain are used to make standard resistances because these alloys have high resistivity and negligible small temperature co -efficient of resistance.
•  Ohms law is not true for all conductors , it is true only for metallic conductors provided physical conditions do not change  
•  Formula V=IR  is true for non ohmic conductors as this formula defines resistance and not Ohms law 
•  Matter is electrical in nature.  It is because every matter is made up of atoms and every atom contains charged particles 
•  Wheatstone circuit is called a bridge because galvanometer bridges the opposite junction
  
  
  s of the circuit .
•  The efficiency of a cell is high when the external resistance is high compared to the internal resistance 
•  Current is a scalar. Because currents at a junction in on electric circuit do not obey the laws of vector algebra 
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