The value of $\cot 70^{\circ} + 4\cos 70^{\circ}$ is

$A$ uniform cube is subjected to volume compression. If each side is decreased by $1\%,$ then the bulk strain is

If the direction cosines of two lines are such that $l+m+n=0$ and $l^2+m^2-n^2=0$,then the angle between them is:

The number of integer values of $m$, for which the $x$-coordinate of the point of intersection of the lines $3x + 4y = 9$ and $y = mx + 1$ is also an integer, is

If the electron of a hydrogen atom is present in the first orbit,the total energy of the electron is

The area (in sq. units) of the region lying in the first quadrant and enclosed by the $X$-axis,the straight line $x-\sqrt{3} y=0$ and the circle $x^2+y^2=4$,is