The angle between the pair of straight lines formed by joining the points of intersection of $x^2+y^2=4$ and $y=3x+c$ to the origin is a right angle. Then $c^2$ is equal to

Calculate the $emf$ of the cell $Cu_{(s)}|Cu^{2+}_{(aq)}||Ag^{+}_{(aq)}|Ag_{(s)}$. Given: $E_{Cu^{2+} / Cu}^0 = +0.34 \ V$,$E_{Ag^{+} / Ag}^0 = 0.80 \ V$.

The increasing order of the atomic radius of $Si, S, Na, Mg, Al$ is

$A$ polaroid is placed at $45^{\circ}$ to an incoming light of intensity $I_0$. Now,the intensity of light passing through the polaroid after polarization would be:

Which one of the following molecular hydrides acts as a Lewis acid?

On a new scale of temperature (which is linear) called the $W$ scale,the freezing and boiling points of water are $39\,^{\circ}W$ and $239\,^{\circ}W$ respectively. What will be the temperature on the new scale,corresponding to a temperature of $39\,^{\circ}C$ on the Celsius scale? ............ $^{\circ}W$