$\int_0^{\pi / 2} \frac{d x}{1+\tan ^3 x}$ is equal to :

If the plane $3x - 2y - z - 18 = 0$ meets the coordinate axes at $A$,$B$,and $C$,then the centroid of $\triangle ABC$ is:

Let $\overrightarrow{a}=\hat{i}-2 \hat{j}+3 \hat{k}$,$\overrightarrow{b}=2 \hat{i}+3 \hat{j}-\hat{k}$ and $\overrightarrow{c}=\lambda \hat{i}+\hat{j}+(2 \lambda-1) \hat{k}$. If $\overrightarrow{c}$ is parallel to the plane containing $\overrightarrow{a}$ and $\overrightarrow{b}$,then $\lambda$ is equal to

One hundred identical coins,each with probability $p$ of showing heads,are tossed once. If $0 < p < 1$ and the probability of heads showing on $50$ coins is equal to that of heads showing on $51$ coins,then the value of $p$ is

The locus of the poles of focal chords of the parabola $y^2 = 4ax$ is

$A$ straight wire carrying current $i$ is turned into a circular loop. If the magnitude of the magnetic moment associated with it in $M.K.S.$ units is $M$,the length of the wire will be