Opening of floral buds into flowers is a type of

$A$ current of $2 \, A$ flows in an electric circuit as shown in the figure. The potential difference $(V_R - V_S)$, in volts ($V_R$ and $V_S$ are potentials at $R$ and $S$ respectively) is:

If $A+B=C$,then the value of $\cos^2 A + \cos^2 B + \cos^2 C - 2 \cos A \cos B \cos C$ is equal to

The wavelengths of electron waves in two orbits is $3: 5$. The ratio of kinetic energy of electrons will be

Which of the following is a long-day plant?

The area of the triangle $ABC$ is $10 \sqrt{3} \text{ cm}^2$,angle $B$ is $60^{\circ}$ and its perimeter is $20 \text{ cm}$,then $\ell(AC) = $ (in $\text{ cm}$)