Let $f(x) = \frac{2\sin^2 x - 1}{\cos x} + \frac{\cos x(2\sin x + 1)}{1 + \sin x}$. Then find $\int e^x (f(x) + f'(x)) dx$ (where $c$ is the constant of integration).

The four distinct points $(0,0), (2,0), (0,-2)$ and $(k,-2)$ are concyclic,if $k$ is equal to

Two parallel rails of a railway track, insulated from each other and from the ground, are connected to a millivoltmeter. The distance between the rails is $1 \, m$. $A$ train is travelling with a velocity of $72 \, km/h$ along the track. What is the reading of the millivoltmeter (in $mV$)? (The vertical component of the Earth's magnetic field is $2 \times 10^{-5} \, T$.)

$ABC$ is a triangular plate of uniform thickness. Its sides are as shown in the figure. If $I_{AB}$,$I_{BC}$,and $I_{CA}$ are the moments of inertia of the plate about axes $AB$,$BC$,and $CA$ respectively,then which of the following relations is correct?

Match the $\frac{C_P}{C_V}$ ratio for ideal gases with different types of molecules:

Molecule type	$\frac{C_P}{C_V}$
$A$. Monoatomic	$I$. $\frac{7}{5}$
$B$. Diatomic rigid molecules	$II$. $\frac{9}{7}$
$C$. Diatomic non-rigid molecules	$III$. $\frac{4}{3}$
$D$. Triatomic rigid molecules	$IV$. $\frac{5}{3}$

Assertion : Comparative biochemistry provides a strong evidence in favour of common ancestry of living beings.
Reason : Genetic code is universal.