Which of the following statement(s) is/are true for tensiometer?
(A) It measures soil water potential.
(B) It is simple in operation and very useful for scheduling irrigation.
(C) It can also be used for measuring soil water flux.
(D) Although limited to <: 1 bar matric potential, this range can be increased by increasing the permeability of its porous cup.
Find the unknown frequency if 24 is the median of the following frequency distribution:
\[\begin{array}{|c|c|c|c|c|c|} \hline \text{Class-interval} & 0-10 & 10-20 & 20-30 & 30-40 & 40-50 \\ \hline \text{Frequency} & 5 & 25 & 25 & \text{$p$} & 7 \\ \hline \end{array}\]