The $IUPAC$ name of the given compound is:

The current in an $LR$ circuit builds up to $\frac{3}{4}$ of its steady-state value in $4 \ s$. The time constant of this circuit is:

The de-Broglie wavelength of a particle moving with a velocity $2.25 \times 10^8 \ m/s$ is equal to the wavelength of a photon. The ratio of the kinetic energy of the particle to the energy of the photon is (velocity of light is $3 \times 10^8 \ m/s$). (in $/8$)

$H_3BO_3$ is

$A$ metal is burnt in air and the ash on moistening smells of $NH_3$. The metal is

If the excess pressure inside a soap bubble is balanced by an oil column of height $2\; mm$,then the surface tension of the soap solution will be ($r = 1\; cm$ and density $d = 0.8\; g/cm^3$).