If $a > 0$ and $b^2 - 4ac = 0$,then the curve $y = ax^2 + bx + c$

The secretion of estrogen is controlled by:

In green plants,cell elongation in the internodal regions is caused by which of the following?

$KMnO_4$ reacts with $KI$ in basic medium to form $I_2$ and $MnO_2$. When $250 \ mL$ of $0.1 \ M \ KI$ solution is mixed with $250 \ mL$ of $0.02 \ M \ KMnO_4$ in basic medium,what is the number of moles of $I_2$ formed?

If the force is given by $F = at + bt^2$,where $t$ is time,the dimensions of $a$ and $b$ are:

The transition from the state $n=3$ to $n=1$ in a hydrogen-like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from: