What are the approximate weight and diameter of $Rafflesia$ $arnoldii$?

The work functions of metals $A$ and $B$ are in the ratio $1 : 2$. If light of frequencies $f$ and $2f$ are incident on the surfaces of $A$ and $B$ respectively,the ratio of the maximum kinetic energies of photoelectrons emitted is (given that $f > f_{0A}$ and $2f > f_{0B}$).

The use of anti-histamine,adrenaline,and steroids quickly reduces the symptoms of:

Cardiac muscle fibers differ from skeletal muscle fibers in that they are -

Which of the following statements is true for $PH_3$?

Which one of the following compounds forms a quaternary salt on reacting with excess methyl iodide?