Which of the following substances is the most acidic?

Four masses are fixed on a massless rod as shown in the figure. The moment of inertia about the axis $PQ$ is about ........ $kg-m^2.$

Which of the following is less general in characters as compared to genus?

$A$ student has to answer $10$ out of $13$ questions in an examination,choosing at least $5$ questions from the first $6$ questions. The number of choices available to the student is:

The sensitivity of a galvanometer is $60 \text{ division/A}$. When a shunt is used,its sensitivity becomes $10 \text{ division/A}$. If the galvanometer is of resistance $20 \ \Omega$,the value of shunt used is: (in $Omega$)

Given below are two statements:-
Statement-$I$: Morphine is a narcotic analgesic. It helps in relieving pain without producing sleep.
Statement-$II$: Morphine and its derivatives are obtained from opium poppy.
In the light of the above statements,choose the correct answer from the options given below.