NEET Physics Current Electricity, Charging & Discharging Of Capacitors / वर्तमान बिजली, चार्ज और कैपेसिटर का निर NEET PYQ-Current Electricity Charging Capacitors

  • question_answer
    A \[5{}^\circ C\] rise in temperature is observed in a conductor by passing a current. When the current is doubled the rise in temperature will be approximately:                                                                                       [AIPMT 1998]

    A)  \[16{}^\circ C\]           

    B)       \[10{}^\circ C\]

    C)  \[20{}^\circ C\]

    D)       \[12{}^\circ C\]

    Correct Answer: C

    Solution :

    [c] Key Idea: When current is passed through a conductor, electric energy is absorbed by the conductor through collisions between its atomic lattice and the charge carriers causing its temperature to rise.
                Energy loss in conductor \[Q={{i}^{2}}RT\]
                Heat developed \[=ms\,\Delta \theta \]
    \[\therefore \]      \[ms\,\Delta \theta ={{i}^{2}}Rt\]
    or         \[\Delta \theta \,\propto \,\,{{i}^{2}}\]
                            \[\frac{\Delta {{\theta }_{2}}}{\Delta {{\theta }_{1}}}=\frac{i_{2}^{2}}{i_{1}^{2}}\]
                or         \[\Delta {{\theta }_{2}}={{\left( \frac{{{i}_{2}}}{{{i}_{1}}} \right)}^{2}}\,\Delta {{\theta }_{1}}\]
                Here      \[{{i}_{2}}=2{{i}_{1}},\,\,\Delta {{\theta }_{1}}={{5}^{o}}C\]
                From Eq. (i)
                \[\therefore \]      \[\Delta {{\theta }_{2}}={{\left( \frac{2{{i}_{1}}}{{{i}_{1}}} \right)}^{2}}\times 5\]
                            \[=4\times 5={{20}^{o}}C\]    


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