What is the concentration of nitrate ions if equal volumes of $0.1 \ M$ $AgNO_3$ and $0.1 \ M$ $NaCl$ are mixed together (in $M$)?

If $y=y(x)$ is the solution of the differential equation $\left(\frac{2+\sin x}{y+1}\right) \frac{d y}{d x}+\cos x=0$ with $y(0)=1$,then $y\left(\frac{\pi}{2}\right)$ is equal to

The angle between the lines whose direction cosines are given by the equations $l^2+m^2-n^2=0$ and $l+m+n=0$ is

$A$ variable plane is at a constant distance $h$ from the origin and meets the coordinate axes in $A, B, C$. The locus of the centroid of $\triangle ABC$ is

Which one of the following correctly represents the variation of electronegativity $(EN)$ with atomic number $(Z)$ of group $13$ elements?

The graphs given below depict the dependence of two reactive impedances $X_1$ and $X_2$ on the frequency of the alternating $e.m.f.$ applied individually to them. We can then say that