Page 713 - SUBSEC October 2017_Neat
P. 713

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                    (h)    A length of Nichrome wire with cross-sectional area 2.60 x 10  m  has a potential
                                                                                       –6
                                                                                           2
                           difference of 100 V across it.  Nichrome has a resistivity of 5.0 x 10  Ωm.  The
                                                                                            –7
                           element dissipates thermal energy at a rate of 500 W.
                           Calculate


                           (i)    the current flowing through the wire

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                                                                                                   [2 marks]


                             (ii)   the resistance of the wire
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                           (iii)   the length of the wire

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                    (i)    Calculate the drift velocity of the electrons, given that each cubic metre of Nichrome
                           contains 9.0 x 10  conduction electrons.
                                           28

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                                                                                                   [2 marks]


                                                                                             Total 30 marks



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