Choose the incorrect statements with respect to chordates
$(A)$ Presence of mid ventral, solid and double nerve cord.
$(B)$ Presence of open circulatory system.
$(C)$ Presence of ventral heart.
$(D)$ Presence of paired pharyngeal gills slits.
$(E)$ Triploblastic acoelomate animals.

A small block of mass $m$ slides down from the top of a frictionless inclined surface, while the inclined plane is moving towards left with constant acceleration $a_{0}$. The angle between the inclined plane and ground is $ heta$ and its base length is $L$. Assuming that initially the small block is at the top of the inclined plane, the time it takes to reach the lowest point of the inclined plane is . . . . . . . .

The incentre of the triangle with vertices $(1, \sqrt{3})$,$(0, 0)$ and $(2, 0)$ is

The $pH$ of $0.1 \ M$ solution of the following salts increases in the order

The molarity of a $0.2 \ N \ Na_2CO_3$ solution will be .......... $M$.

The solution of the differential equation $\frac{dy}{dx} = \frac{y}{x} + \frac{\phi(y/x)}{\phi'(y/x)}$ is