Among the species given below, the total number of diamagnetic species is. . . . . $H$ atom, $NO _2$ monomer, $O _2^{-}$(superoxide), dimeric sulphur in vapour phase, $MnsO _4$, $\left( NH _4\right)_2\left[ FeCl _4\right],\left( NH _4\right)_2\left[ NiCl _4\right], K _2 MnO _4, K _2 CrO _4$

If $a, b$ and $c$ form a geometric progression with common ratio $r$,then the sum of the ordinates of the points of intersection of the line $ax + by + c = 0$ and the curve $x + 2y^2 = 0$ is

At $25^{\circ} C$, the concentration of $H ^{+}$ions in $1.00 \times 10^{-3} M$ aqueous solution of a weak monobasic acid having acid dissociation constant $\left(K_a\right)=4.00 \times 10^{-11}$ is $X \times 10^{-7} M$. The value of $X$ is $...$ .
Use: Ionic product of water $\left(K_w\right)=1.00 \times 10^{-14}$ at $25^{\circ} C$

In an astronomical telescope in normal adjustment,a straight black line of length $L$ is drawn on the inside part of the objective lens. The eyepiece forms a real image of this line. The length of this image is $I$. The magnification of the telescope is

If the angles of a triangle are in the ratio $4:1:1,$ then the ratio of the longest side to the perimeter is

If $2.2 \, kW$ power is transmitted through a $10 \, \Omega$ line at $22000 \, V$,the power loss in the form of heat will be ............. $W$.