Which of the following statements is correct?

$A$ capillary tube of radius '$r$' is immersed in water and water rises to a height of '$h$'. The mass of water in the capillary tube is $5 \times 10^{-3} \ kg$. The same capillary tube is now immersed in a liquid whose surface tension is $\sqrt{2}$ times the surface tension of water. The angle of contact between the capillary tube and this liquid is $45^{\circ}$. The mass of liquid which rises into the capillary tube now is (in $kg$):

When a certain metallic surface is illuminated with monochromatic light of wavelength $\lambda$,the stopping potential for photoelectric current is $3V_0$. When the same surface is illuminated with light of wavelength $2\lambda$,the stopping potential is $V_0$. The threshold wavelength of this surface for the photoelectric effect is:

What is the hybridization state of the central atom in the conjugate base of $NH_4^{+}$ ion?

Which of the following statements is true?

If $p \rightarrow (\sim p \vee q)$ is false,then the truth values of $p$ and $q$ are,respectively