Which of the following compounds lacks iron?

$\int_{-1}^1 \frac{\cosh x}{1+e^{2 x}} d x$ is equal to :

The refractive index of a material of a plano-concave lens is $5/3$,and the radius of curvature is $0.3 ~m$. The focal length of the lens in air is (in $~m$)

Which one of the following conditions is incorrect for a well-behaved wave function $(\psi)$?

$A$ thin wire of length $l$ and mass $M$ is bent in the form of a semicircle. What is its moment of inertia about an axis passing through the ends of the wire?

The force between the plates of a parallel plate capacitor of capacitance $C$ and distance of separation of the plates $d$ with a potential difference $V$ between the plates,is