NEET AIPMT SOLVED PAPER SCREENING 2004

  • question_answer
    In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be:   

    A) \[R\]                             

    B) \[2R\]                           

    C) \[\frac{R}{4}\]          

    D) \[\frac{R}{2}\]

    Correct Answer: C

    Solution :

            Since, power rating of bulb in both the countries India and USA should be same, so \[\frac{V_{1}^{2}}{{{R}_{1}}}=\frac{V_{2}^{2}}{{{R}_{2}}}\] \[\Rightarrow \]       \[\frac{220\times 220}{{{R}_{1}}}=\frac{110\times 110}{{{R}_{2}}}\] \[\Rightarrow \]       \[\frac{{{R}_{2}}}{{{R}_{1}}}=\frac{110\times 110}{220\times 220}\] \[\Rightarrow \]       \[{{R}_{2}}=\frac{R}{4}\]                                               \[(\because {{R}_{1}}=R)\]


You need to login to perform this action.
You will be redirected in 3 sec spinner