CET Karnataka Medical CET - Karnataka Medical Solved Paper-2005

  • question_answer
    If the potential difference across the internal resistance r1 is equal to the emf E of the battery, then:

    A)  \[R={{r}_{1}}+{{r}_{2}}\]

    B)  \[R=\frac{{{r}_{1}}}{{{r}_{2}}}\]

    C)  \[R={{r}_{1}}-{{r}_{2}}\]

    D)  \[R=\frac{{{r}_{2}}}{{{r}_{1}}}\]

    Correct Answer: C

    Solution :

    The total emf = E + E = 2E Total resistance \[=R+{{r}_{1}}+{{r}_{2}}\] \[\therefore \]Current flowing through the circuit \[i=\frac{2E}{R+{{r}_{1}}+{{r}_{2}}}\] According to question \[E=i{{r}_{1}}\Rightarrow i=\frac{E}{{{r}_{1}}}\] \[\therefore \] \[\frac{E}{{{r}_{1}}}=\frac{2E}{R+{{r}_{1}}+{{r}_{2}}}\]


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