Which of the following is not produced during the electrolysis of brine solution?

When the same quantity of electricity is passed through aqueous $AgNO_3$ and $H_2SO_4$ solutions connected in series,$5.04 \times 10^{-2} \ g$ of $H_2$ is liberated. What is the mass of silver (in grams) deposited? (Eq. wts. of hydrogen $= 1.008$,silver $= 108$)

The mean of four observations is $3$. If the sum of the squares of these observations is $48$,then their standard deviation is

For a first order reaction at $27^{\circ} C$,the ratio of time required for $75 \%$ completion to $25 \%$ completion of reaction is

Shown in the figure is a conductor carrying a current $I$. The magnetic field intensity at the point $O$ (common centre of all the three arcs) is

Given the circle $C$ with the equation $x^2+y^2-2x+10y-38=0$. Match the List-$I$ with the List-$II$ given below concerning $C$.

$A$. The equation of the polar of $(4, 3)$ with respect to $C$	$I$. $y + 5 = 0$
$B$. The equation of the tangent at $(9, -5)$ on $C$	$II$. $x = 1$
$C$. The equation of the normal at $(-7, -5)$ on $C$	$III$. $3x + 8y = 27$
$D$. The equation of the diameter passing through $(1, -5)$ and $(1, 3)$	$IV$. $x = 9$