NEET AIPMT SOLVED PAPER 2000

  • question_answer
                    Two bulbs 25 W, 220 V and 100 W, 220 V are given. Which has higher resistance?              

    A)                 25 W bulb           

    B)                        100 W bulb

    C)                 Both bulbs will have equal resistance     

    D)                 Resistance of bulbs cannot be compared

    Correct Answer: A

    Solution :

                    Power of electric bulb                 \[P=\frac{{{V}^{2}}}{2R}\]                 So, resistance of electric bulb                 \[R=\frac{{{V}^{2}}}{P}\]                 Given, \[{{P}_{1}}=25\,W,\,\,{{P}_{2}}=100\,W,\,{{V}_{1}}={{V}_{2}}=220\,V\]                 Therefore, for same potential difference V,                 \[R\,\propto \,\,\frac{1}{P}\]                 Thus, we observe that for minimum power, resistance will be maximum and vice-versa.                 Hence, resistance of 25 W bulb is maximum and 100 W bulb is minimum.


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