Exhausted permutit does not contain $.......$ ion.

If the power dissipated in the $3\,\Omega$ resistor is $27\,W$,what is the power dissipated in the $2\,\Omega$ resistor (in $,W$)?

The idea of secondary wavelets for the propagation of a wave was first given by

An object of mass $0.2 \, kg$ executes simple harmonic motion along the $X$-axis with a frequency of $\frac{25}{\pi} \, Hz$. At the position $x = 0.04 \, m$,the object has a kinetic energy of $0.5 \, J$ and a potential energy of $0.4 \, J$. The amplitude of oscillation in meters is equal to:

In a biprism experiment,if the $5^{\text{th}}$ bright band with wavelength $\lambda_{1}$ coincides with the $6^{\text{th}}$ dark band with wavelength $\lambda_{2}$,then the ratio $\left(\frac{\lambda_{2}}{\lambda_{1}}\right)$ is:

Which one of the following is not an essential mineral element for plants while the remaining three are?