A long solenoid with $15\; turns\; per\; cm$ has a small loop of area $2.0cm^2$ placed inside the solenoid normal to its axis. If the current carried by the solenoid changes steadily from $2.0 A \; to \;4.0 A$ in $0.1 S ,$ what is the induced $emf$ in the loop while the current is changing?

Question

$(A) 7.5 \times 10^6V$
$(B)\; 7.5 \times 10^{-6}V$
$(C)\; 7.5 \times 10^5 V$
$(D)\; 7.5 \times 10^{-5}V$