$A$ stationary wave is represented by $y = 10 \sin \frac{\pi x}{4} \cos 20 \pi t$,where $x$ and $y$ are expressed in $cm$ and $t$ in seconds. The distance between two consecutive nodes is: (in $cm$)

Which one of the following is not a second messenger in hormone action?

Acetaldehyde cannot give:

$A$ physical quantity $X$ is given by $X = \frac{2 k^3 \ell^2}{m \sqrt{n}}$. The percentage errors in the measurement of $k, \ell, m,$ and $n$ are $1\%, 2\%, 3\%,$ and $4\%$ respectively. The percentage uncertainty in the value of $X$ is: (in $\%$)

What is the order of reactivity of halogen acids with $C_2H_5OH$?

If a straight line perpendicular to $2x - 3y + 7 = 0$ forms a triangle with the coordinate axes whose area is $3 \text{ sq. units}$,then the equation of the straight line is: