In which plant group are the sporophylls arranged spirally along an axis to form distinct compact structures called strobili or cones?

Identify the plant shown in the given figure.

If $\left[\begin{array}{rrr}1 & 2 & x \\ 4 & -1 & 7 \\ 2 & 4 & -6\end{array}\right]$ is a singular matrix,then $x$ is equal to

$A$ mass of $0.5\, kg$ moving with a speed of $1.5\, m/s$ on a horizontal smooth surface,collides with a nearly weightless spring of force constant $k=50\, N/m$. The maximum compression of the spring would be ................. $m$.

$Fe$ is made passive by

Three bulbs of $40\, W$,$60\, W$,and $100\, W$ are connected in series to a $220\, V$ supply. Which bulb has the minimum resistance?