Which of the following aquatic ferns is used as an excellent biofertilizer?

An $n-p-n$ transistor power amplifier in $C-E$ configuration gives

Which of the following solutions has osmotic pressure nearer to that of an equimolar solution of $K_4[Fe(CN)_6]$?

$2 \tanh^{-1} \frac{1}{2}$ is equal to

$A$ bus moving on a level road with a velocity $v$ can be stopped at a distance of $x$,by the application of a retarding force $F$. The load on the bus is increased by $25 \%$ by boarding the passengers. Now,if the bus is moving with the same speed and if the same retarding force is applied,the distance travelled by the bus before it stops is

Let $O$ be the vertex and $Q$ be any point on the parabola $x^2 = 8y$. If the point $P$ divides the line segment $OQ$ internally in the ratio $1:3$,then the locus of $P$ is: