2. Sample Papers
  3. NEET

NEET Sample Paper NEET Sample Test Paper-23

  • question_answer
    The potentiometer wire AB shown in the adjoining figure is 100 cm long when AD = 30 cm, no deflection occurs in the galvanometer. The value of R is:

    A)  \[6\Omega \]                          

    B) \[9\Omega \]

    C) \[14\Omega \]                         

    D) \[15\Omega \]               

    Correct Answer: C

    Solution :

    Let \[\rho \]be the resistance per unit length of the potentiometer wire AB. If D is the balance point, then from the condition of balance of wheat stone's bridge \[\frac{P}{Q}=\frac{R}{S}\]or \[\frac{6}{R}=\frac{30\rho }{(100-30)\rho }=\frac{30}{70}=\frac{3}{7}\] or, \[R=\frac{7\times 6}{3}=14\Omega \] Hence, the correction option is [c].


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