When the number of turns in a coil is doubled without any change in the length of the coil,its self-inductance becomes

$A$ graph of magnetic flux ( $\phi$ ) versus current $(I)$ is shown for four inductors $A, B, C, D$. The smaller value of self-inductance is for inductor:

$A$ circuit having a self-inductance of $1 \text{ H}$ carries a current of $1 \text{ A}$. To prevent sparking when the circuit is broken,a capacitor which can withstand $500 \text{ V}$ is connected across the switch. What is the minimum value of the capacitance of the capacitor (in $\mu \text{ F}$)?

In the part of an a.c. circuit as shown,the resistance $R=0.2 \ \Omega$. At a certain instant,$(V_{A}-V_{B})=0.5 \ V$,$I=0.5 \ A$ and $\frac{dI}{dt}=8 \ A/s$. The inductance of the coil is (in $H$)

When the current through a solenoid increases at a constant rate, the induced current