Which one of the following salts gives an acidic solution in water?

$A$ body of mass $0.01 \ kg$ executes simple harmonic motion $(S.H.M.)$ about $x = 0$ under the influence of a force shown in the graph. The period of the $S.H.M.$ is .... $s$

The work function of a metal is $4.2 \ eV$. Its threshold wavelength will be ............ $\mathring{A}$.

The ratio between kinetic energy and the total energy of the electrons of a hydrogen atom according to Bohr's model is

The equation of a stationary wave is $y = 0.8 \cos \left( \frac{\pi x}{20} \right) \sin (200 \pi t)$,where $x$ is in $cm$ and $t$ is in $sec$. The separation between consecutive nodes will be..... $cm$.

What is a phycobiont?