2. Questions Bank
  3. 10th Class
  4. Science
  5. Electricity and Circuits

10th Class Science Electricity and Circuits Question Bank Electricity

  • question_answer
    Two cells of same emf E but different internal resistances \[{{r}_{1}}\] and \[{{r}_{2}}\] are connected in series with an external resistance R. The potential drop across the first cell is found to be zero. The external resistance R is

    A)  \[{{r}_{1}}+{{r}_{2}}\]          

    B)       \[{{r}_{1}}-{{r}_{2}}\]  

    C)  \[{{r}_{2}}-{{r}_{1}}\]           

    D)       \[{{r}_{1}}{{r}_{2}}\]

    Correct Answer: B

    Solution :

     The drop across the internal resistance of first cell \[{{r}_{1}}\] is\[E\]. So, the total drop across \[{{r}_{2}}\] and must also be\[E\]                 \[I{{r}_{1}}=I({{r}_{2}}+R)\](in series,\[I\]is same) \[\therefore \]  \[R={{r}_{1}}-{{r}_{2}}\]


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