Smooth muscles are:

$A$ black body at a temperature of $227^{\circ}C$ radiates heat energy at the rate of $5 \ cal/cm^2-sec$. At a temperature of $727^{\circ}C$,the rate of heat radiated per unit area in $cal/cm^2-sec$ will be:

$\sec ^2(\tan ^{-1} 2) + \operatorname{cosec}^2(\cot ^{-1} 3)$ is equal to

If three unit vectors $\overrightarrow{a}, \overrightarrow{b}, \overrightarrow{c}$ satisfy $\overrightarrow{a}+\overrightarrow{b}+\overrightarrow{c}=\overrightarrow{0}$, then the angle between $\overrightarrow{a}$ and $\overrightarrow{b}$ is

Which of the following anthropogenic actions leads to evolution?

The most popularly known blood grouping is the $ABO$ grouping. It is named $ABO$ and not $ABC$,because '$O$' in it refers to having