Which of the following complexes is an outer orbital complex?

An ideal gas undergoes a quasi-static, reversible process in which its molar heat capacity $C$ remains constant. If during this process the relation of pressure $P$ and volume $V$ is given by $PV^n = \text{constant}$, then $n$ is given by (Here $C_P$ and $C_V$ are molar specific heat at constant pressure and constant volume, respectively).

In the circuit shown in the figure,the reading of the voltmeter is $V_1$ when only $S_1$ is closed,the reading of the voltmeter is $V_2$ when only $S_2$ is closed,and the reading of the voltmeter is $V_3$ when both $S_1$ and $S_2$ are closed. Then:

Assertion $(A)$: $A$ particle of mass $m$ dropped into a hole made along the diameter of the Earth from one end to the other executes simple harmonic motion.
Reason $(R)$: Gravitational force between any two particles is inversely proportional to the square of the distance between them.

Three numbers are chosen at random from $1$ to $20$. The probability that they are consecutive is

What is the electronic arrangement of a metal atom/ion in an octahedral complex with a $d^4$ configuration,if $\Delta_0 < P$ (pairing energy)?