question_answer

Two coils are wound on the same iron rod so that the flux generated by one passes through the other. The primary coil has Np turns in it and when a current 2A flows through it the flux in it is \[2.5\times {{10}^{-4}}Wb.\] If the secondary coil has 12 turns the mutual inductance of the coils is (assume the secondary coil is in open circuit)

A) \[10\times {{10}^{-4}}H\]                            

B)  \[15\times {{10}^{-4}}H\]

C)  \[20\times {{10}^{-4}}H\]                           

D)  \[25\times {{10}^{-4}}H\]