$A$ Zener diode,having a breakdown voltage equal to $15\, V$,is used in a voltage regulator circuit as shown in the figure. The current through the Zener diode is.....$mA$.

The correct order as indicated in each option is:

The electronic configurations of $Cr^{2+}, Mn^{2+}, Fe^{2+},$ and $Ni^{2+}$ are $3d^4, 3d^5, 3d^6,$ and $3d^8$ respectively. Which one of the following aqua complexes will exhibit the minimum paramagnetic behavior?

The equation of the tangent to the curve $6y = 7 - x^3$ at the point $(1, 1)$ is:

If $\int \frac{dx}{x^2+2x+2} = f(x) + c$, then $f(x)$ is equal to :

Two cylinders $A$ and $B$ fitted with pistons contain equal amounts of an ideal diatomic gas at $300\ K.$ The piston of $A$ is free to move while that of $B$ is held fixed. The same amount of heat is given to the gas in each cylinder. If the rise in temperature of the gas in $A$ is $30\ K,$ then the rise in temperature of the gas in $B$ is ....... $K$