The formula for exponential population growth is

$A$ body projected vertically upwards crosses a point twice in its journey at a height $h$ just after $t_1$ and $t_2$ seconds. Maximum height reached by the body is

Two circular coils $A$ and $B$ are facing each other as shown in the figure. The current $i$ through coil $A$ can be altered.

If $(1, a)$ and $(b, 2)$ are conjugate points with respect to the circle $x^2+y^2=25$,then $4a+2b$ is equal to

Heat required to melt $1\, g$ of ice is $80\, cal$. $A$ man melts $60\, g$ of ice by chewing in one minute. His power is ........ $W$.

........ of a reaction cannot be determined experimentally.