In biennial plants,the number of carpels is normally:

Electrons from excited chlorophyll molecule of photosystem $II$ are accepted first by

Which one of the following statements is not correct?

The amplitude of a damped oscillator decreases to $0.9$ times its original magnitude in $5\,s$. In another $10\,s$ it will decrease to $\alpha$ times its original magnitude,where $\alpha$ equals

$\begin{aligned} & f(x, y)=2(x-y)^2-x^4-y^4 \\ & \left|\left(f_{x x} f_{y y}-f_{x y}^2\right)\right|_{(0,0)} \end{aligned}$

The heat energy absorbed by a system undergoing the cyclic process shown in the figure is: