Which of the following is a fossil Pteridophyte?

Three rods of equal length $l$ are joined to form an equilateral triangle $PQR.$ $O$ is the midpoint of $PQ.$ The distance $OR$ remains the same for a small change in temperature. The coefficient of linear expansion for $PR$ and $RQ$ is the same,i.e.,$\alpha_2,$ but that for $PQ$ is $\alpha_1.$ Then the relation between $\alpha_1$ and $\alpha_2$ is:

Match the following columns:

Column-$I$	Column-$II$
$a$. Superior Vena Cava	$p$. Carries deoxygenated blood to the lungs
$b$. Inferior Vena Cava	$q$. Carries oxygenated blood to the heart
$c$. Pulmonary Artery	$r$. Brings deoxygenated blood from lower body parts to the right atrium
$d$. Pulmonary Vein	$s$. Brings deoxygenated blood from upper body parts to the right atrium

Which of the following is an acidic salt?

Which of the following is incorrect for garden pea?

How many numbers greater than $24000$ can be formed by using digits $1, 2, 3, 4, 5$ when no digit is repeated?