Which one of the following is a slime mould?

An inductor $L$,a resistance $R$ and two identical bulbs $B_1$ and $B_2$ are connected to a battery through a switch $S$ as shown in the figure. The resistance of the coil having inductance $L$ is also $R$. Which of the following statements gives the correct description of the happenings when the switch $S$ is closed?

In the conversion of a zinc ore to zinc metal,the process of roasting involves:

The first diffraction minimum due to a single slit diffraction is seen at $\theta = 30^o$ for light of wavelength $5000 \, \mathring{A}$ falling perpendicularly on the slit. The width of the slit is

An ellipse passing through $(4 \sqrt{2}, 2 \sqrt{6})$ has foci at $(-4, 0)$ and $(4, 0)$. Then,its eccentricity is

The number of turns in the primary and secondary coils of a transformer are $50$ and $200$ respectively. If the current in the primary coil is $4 ~A$,then the current in the secondary coil is: (in $~A$)