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 \[{{N}_{p}}\] 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) \[25\times {{10}^{-4}}H\]