$Na_2S_2O_3$ reacts with moist $Cl_2$ to form $Na_2SO_4$,$HCl$ and $X$. Which one of the following is $X$?

In which of the following arrangements,the order is not correct according to the property indicated against it?

Choose the incorrect pair for the characters given by Mendel regarding dominance and recessiveness.

$A$ simple harmonic progressive wave is given by $y = y_0 \sin 2 \pi (nt - \frac{x}{\lambda})$. If the wave velocity is $\left(\frac{1}{8}\right)^{\text{th}}$ of the maximum particle velocity,then the wavelength is:

The truth table for the system of four $NAND$ gates as shown in the figure is:

The equations of the circle which pass through the origin and make intercepts of lengths $4$ and $8$ on the $x$ and $y$-axes respectively are