Which of the following is the characteristic outer electronic configuration of alkaline earth metals?

The locus of the poles of focal chords of the parabola $y^2 = 4ax$ is

For a telescope,the focal length of the objective lens is $15 \ cm$ and the focal length of the eyepiece is $10 \ mm$. If the tube length is $16 \ cm$,find the magnification.

An inductance $L$ having a resistance $R$ is connected to an alternating source of angular frequency $\omega$. The Quality factor $Q$ of the inductance is

$\left|\begin{array}{ccc}x+2 & x+3 & x+5 \\ x+4 & x+6 & x+9 \\ x+8 & x+11 & x+15\end{array}\right|$ is equal to

Which of the following compounds will react with $NaHCO_3$ solution to give sodium salt and carbon dioxide?