Which element is located at the center of the porphyrin ring in chlorophyll?

In the circuit shown in the figure,the potential difference between points $A$ and $B$ is $16 \, V$. The current passing through the $2 \, \Omega$ resistance will be ................. $A$.

$A$ Young's double slit experiment uses a monochromatic source. The shape of the interference fringes formed on a screen is

The roots of the equation $x^3-14x^2+56x-64=0$ are in

Which pair of substances gives the same gaseous product when they react with water?

If $m_1$ and $m_2$ are the roots of the equation $x^2+(\sqrt{3}+2) x+(\sqrt{3}-1)=0$,then the area of the triangle formed by the lines $y=m_1 x, y=m_2 x$ and $y=c$ is: