The concentration of a $100 \ mL$ solution containing $X \ g$ of $Na_2CO_3$ (molecular weight $= 106$) is $Y \ M$. The values of $X$ and $Y$ are respectively.

$A$ point object is placed at a distance of $30 \, cm$ from a convex mirror of focal length $30 \, cm$. The image will form at

Specific heats of an ideal gas at constant pressure and volume are denoted by $C_p$ and $C_v$ respectively. If $\gamma = \frac{C_p}{C_v}$ and $R$ is the universal gas constant,then $C_v$ is equal to:

Which of the following taxonomical aids is being described by the given statements $(i-iv)$?
$(i)$. They are generally established in educational institutes.
$(ii)$. They have collections of preserved plant and animal specimens for study and reference.
$(iii)$. Insects are preserved in boxes after collecting,killing and pinning.
$(iv)$. They often have collections of skeletons of animals too.

Magnetic induction at the centre of a circular loop of area $\pi \ m^2$ is $0.1 \ T$. The magnetic moment of the loop is ( $\mu_0 = \text{permeability of air}$ ).

Which of the following statements is not correct when a junction diode is in forward bias?