The negation of the statement pattern $\sim p \vee (q \rightarrow \sim r)$ is

If $\int \frac{e^x-1}{e^x+1} d x=f(x)+c$,then $f(x)$ is equal to

Which of the following oxides reacts with both $HCl$ and $NaOH$?

Three rings,each having equal radius $R$,are placed mutually perpendicular to each other and each having its centre at the origin of the coordinate system. If current $I$ is flowing through each ring,then the magnitude of the magnetic field at the common centre is

$A$ concave mirror gives an image three times as large as the object placed at a distance of $20 \ cm$ from it. For the image to be real,the focal length should be ...... $cm$.

The specific rotation of the equilibrium mixture of $\alpha-D$-glucose and $\beta-D$-glucose is ....... $^\circ$.