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

The energy emitted per second by a black body at $27^{\circ}C$ is $10 \ J$. If the temperature of the black body is increased to $327^{\circ}C$,the energy emitted per second will be ......... $J$.

If the circle $x^2+y^2+6x-2y+k=0$ bisects the circumference of the circle $x^2+y^2+2x-6y-15=0$,then $k=$

If $\frac{e^x + 2}{(e^x - 1)(2e^x - 3)} = -\frac{3}{e^x - 1} + \frac{B}{2e^x - 3}$,then $B = $

Which combination of tissues acts together to provide support to the hypocotyl of a seedling?

Which of the following figures represents the variation of particle momentum $p$ and the associated de-Broglie wavelength $\lambda$?