Electromagnetic Induction Ques 15

15. A long solenoid has $1000$ turns. When a current of $4$ $ A$ flows through it, the magnetic flux linked with each turn of the solenoid is $4 \times 10^{-3} Wb$. The self inductance of the solenoid is :

[2016]

(a) $4 $ $H$

(b) $3 $ $H$

(c) $2 $ $H$

(d) $1 $ $H$

Show Answer

Answer:

Correct Answer: 15.(d)

Solution:

  1. (d) Here, number of turns $n=1000$;

current through the solenoid $i=4 $ $A$;

flux linked with each turn $=4 \times 10^{-3} $ $Wb$

$\therefore$ Total flux linked,

$=1000[4 \times 10^{-3}]=4 $ $Wb$

$\phi _{\text{total }}=4 \Rightarrow Li=4$

$\Rightarrow L=1 $ $H$

Number of flux linkages with the coil $\propto$ current $(I)$

$ N \phi \propto I \Rightarrow N \phi=L_I \Rightarrow L=\frac{N \phi}{I} . $