Which of the following represents a surfactant molecule?

If $A=\left[\begin{array}{rr}i & -i \\ -i & i\end{array}\right]$ and $B=\left[\begin{array}{rr}1 & -1 \\ -1 & 1\end{array}\right]$,then find $A^8$. (in $B$)

Two electric bulbs rated $P_1 \text{ watt}, V \text{ volt}$ and $P_2 \text{ watt}, V \text{ volt}$ are connected in parallel and $V \text{ volt}$ is applied to them. The total power consumed will be

The phase difference between input and output voltage of a $CE$ circuit is.......$^o$

Taxonomic hierarchy refers to

In order to eliminate the first degree terms from the equation $2x^2+4xy+5y^2-4x-22y+7=0$,the point to which the origin is to be shifted is