Page 53 - CHAPTER-1 (Electricity)
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CHAPTER 1

            ELECTRICITY


           Ans.(a)Tungsten  possesses  a  very  high  melting  point  (3380°C)  and

           becomes  incandescent  (i.e.,  it  starts  emitting  light  at  a  very  high

           temperature) at 2400 K.


           (b)  The resistivity of some alloy is generally higher than that of pure

           metals of which it is made of.

           (c)  In the series arrangement, if any one of the appliances fails or is

           switched off, all the other appliances stop working  since the same


           current passes through all the appliances.

           (d)  The  resistance  of  any  wire  (R)  varies  inversely  with  its  cross-

           sectional area (A) as R ∝ 1/A.


           (e). Aluminium and copper wires possess low resistivity and as such

           are generally used     for electricity transmission.



















































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