Which relation is correct for an isochoric process?

In which of the following is the $P - O - P$ bond present?

$A$ light ray of wavelength $\lambda$ is passing through a pinhole of diameter $D$ and the effect is observed on a screen placed at a distance $L$ from the pinhole. The approximations of geometrical optics are applicable,if

The maximum area of a right-angled triangle with hypotenuse $h$ is

Taxonomic hierarchy refers to

Which of the following is not an essential amino acid?