JEE Main & Advanced JEE Main Solved Paper-2014

  • question_answer
    10. In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW. The voltage of the electric mains is 220 V. The minimum capacity of the main fuse of the building will be :   JEE Main  Solved  Paper-2014

    A) 12 A

    B) 14 A

    C) 8 A                                         

    D) 10 A

    Correct Answer: A

    Solution :

    \[\frac{1}{{{\operatorname{R}}_{eq}}}=\frac{1}{{{\operatorname{R}}_{1}}}+\frac{1}{{{\operatorname{R}}_{2}}}\] \[P=\frac{{{V}^{2}}}{{{\operatorname{R}}_{eq}}}=\frac{{{V}^{2}}}{{{\operatorname{R}}_{1}}}+\frac{{{V}^{2}}}{{{\operatorname{R}}_{2}}}+.......\] \[=15\times 40+5\times 100+80\times 5+1\times 1000=2500w\] \[P=VI\] \[P=2500=220I\] \[I=\frac{250}{22}=\frac{125}{11}\]                                


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