AMU Medical AMU Solved Paper-2000

  • question_answer
    A coil of mean area 500 \[c{{m}^{2}}\] and having 1000 turns is held perpendicular to a uniform field of 0.4 gauss. The coil is turned through \[180{}^\circ \] in s the average induced emf will be

    A)  0.08 V                                  

    B)  0.16 V

    C)  1.6 V                                    

    D)  0.04 V

    Correct Answer: D

    Solution :

                     From Faradays law of electromagnetic induction, the induced emf (e) is given by                 \[e=-\frac{\Delta \phi }{\Delta t}n\]                        ... (i) where \[\Delta \phi \] is rate of change of magnetic flux, given by                 \[\Delta \phi =B\,.\,\,A=BA\cos \theta \]              ... (ii) where B is magnetic field intensity and A is area. Since coil is turned through 180° change in flux is                 \[\Delta \phi =BA-(-BA)=2BA\] \[\therefore \]  \[e=-\frac{2\,BAn}{\Delta t}\] Given,   \[B=0.4\times {{10}^{-4}}T\]                 \[A=500\,c{{m}^{2}}\]                 \[=500\times {{({{10}^{-2}})}^{2}}{{m}^{2}}\]                 \[\Delta t=\frac{1}{10}s\],            n = 1000                 \[e=-\frac{2\times 0.4\times 500\times {{10}^{-4}}\times 1000\times {{10}^{-4}}}{1/10}\] \[\Rightarrow \]               \[e=0.04\]


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