2. Sample Papers
  3. NEET

NEET Sample Paper NEET Sample Test Paper-18

  • question_answer
    The figure shows three similar lamps \[{{L}_{1}},{{L}_{2}},\]and \[{{L}_{3}}\]connected across a power supply. If the lamp \[{{L}_{3}}\]fuse, how will the light emitted by \[{{L}_{1}}\]and\[{{L}_{2}}\]charge?

    A)  No charge

    B)  Brilliance of \[{{L}_{1}}\]decreases and that of \[{{L}_{2}}\]increases

    C)  Brilliance of both \[{{L}_{1}}\]and \[{{L}_{2}}\]increases

    D)  Brilliance of both \[{{L}_{1}}\]and \[{{L}_{2}}\]decreases

    Correct Answer: B

    Solution :

    Let R be the resistance of each lamp. If E be the applied e. m. f. then the current in the circuit I, is given by \[{{I}_{1}}=\frac{E}{R+(R/2)}=\frac{2E}{3R}\] Current flowing through \[{{L}_{2}}\] or \[{{L}_{2}}\] When\[{{L}_{3}}\]is fused, the whole current flows through\[{{L}_{1}}\] and \[{{L}_{1}}.\]Thus \[{{I}_{2}}=\frac{E}{2R}\] So, current through \[{{L}_{1}}\]decreases and through \[{{L}_{2}}\]increases. Hence, the correction option is [b].


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