$A$ balloon is filled with $500 \ m^3$ of helium gas at $27^{\circ}C$ and $1 \ atm$ pressure. What will be the volume of helium at $3^{\circ}C$ and $0.5 \ atm$ pressure in $m^3$?

In $Pteridophytes$,reduction division occurs when -

Which of the following orders is correct for the heat of hydrogenation of these compounds?

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.

If $A=35^{\circ}, B=15^{\circ}$ and $C=40^{\circ}$,then $\tan A \cdot \tan B+\tan B \cdot \tan C+\tan C \cdot \tan A$ is equal to

If the curves $y^2=6x$ and $9x^2+by^2=16$ intersect each other at right angles,the value of $b$ is