JCECE Medical JCECE Medical Solved Paper-2005

  • question_answer
    If a transformer of an audio amplifier has output impedance 8000 0 and the speaker has input impedance of 80, the primary and secondary turns of this transformer connected

    A)  1000 : 1       

    B)  100 : 1

    C)  1 : 32        

    D)  32 : 1

    Correct Answer: A

    Solution :

     From Faraday's law, the induced emf across primary and secondary is \[{{e}_{p}}=-{{N}_{p}}\frac{\Delta \text{o}|}{\Delta t}\] \[{{e}_{s}}=-{{N}_{s}}\frac{\Delta \text{o}|}{\Delta t}\] Also, \[e=iR\] \[\therefore \] \[\frac{{{R}_{p}}}{{{R}_{s}}}=\frac{{{N}_{p}}}{{{N}_{s}}}\] Given, \[{{R}_{s}}=8000\,\Omega ,{{R}_{p}}=8\,\Omega \] \[\therefore \] \[\frac{{{N}_{s}}}{{{N}_{p}}}=\frac{{{R}_{s}}}{{{R}_{p}}}=\frac{8000}{8}=\frac{1000}{1}\]


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