Which alga exhibits a haplo-diplontic life cycle?

Two circles whose radii are equal to $4$ and $8$ intersect at right angles. The length of their common chord is

$A$ $Ge$ specimen is doped with $Al$. The concentration of acceptor atoms is $\sim 10^{21} \text{ atoms}/m^3$. Given that the intrinsic concentration of electron-hole pairs is $\sim 10^{19} /m^3$,the concentration of electrons in the specimen is:

Which gas is released when $Na_2CO_3$ is heated?

If $3 \cos x \neq 2 \sin x$,then the general solution of $\sin^2 x - \cos 2x = 2 - \sin 2x$ is

The major product $A$ is: