The coefficient of $x^5$ in the expansion of $(1 + x)^{21} + (1 + x)^{22} + \dots + (1 + x)^{30}$ is

Fight-or-flight reactions cause activation of

Which of the following bonds has the highest energy?

$A$ wire of length $l$ is bent into a circular loop of radius $R$ and carries a current $I$. The magnetic field at the centre of the loop is $B$. The same wire is now bent into a double loop of equal radii. If both loops carry the same current $I$ and it is in the same direction,the magnetic field at the centre of the double loop will be

If the centroid of the triangle formed by the lines $2y^2 + 5xy - 3x^2 = 0$ and $x + y = k$ is $\left(\frac{1}{18}, \frac{11}{18}\right)$,then the value of $k$ equals $............$

Young's double-slit experiment is carried out by using green,red,and blue light,one color at a time. The fringe widths recorded are $\beta_G, \beta_R$,and $\beta_B$ respectively. Then: