The atomic weights of two elements $A$ and $B$ are $40$ and $80$ respectively. If $x \ g$ of $A$ contains $y$ atoms,how many atoms are present in $2x \ g$ of $B$?

$A$ particle of mass $M$ starting from rest undergoes uniform acceleration. If the speed acquired in time $T$ is $V$,then the power delivered to the particle in time $T$ is:

Stimulation of a muscle fiber by a motor neuron occurs at:

How many moles of $KMnO_4$ are required to oxidize $1 \ mol$ of $FeC_2O_4$ in an acidic medium?

If $\frac{x-4}{x^2-5x-2k} = \frac{2}{x-2} - \frac{1}{x+k}$,then $k$ is equal to

If $f$ is a differentiable function such that $f(2x+1) = f(1-2x)$ for all $x \in R$,then what is the minimum number of roots of the equation $f'(x) = 0$ in the interval $x \in (-5, 10)$,given that $f(2) = f(5) = f(10)$?