What is the cytoskeleton composed of?

The element having the electronic configuration $[Kr] 4d^{10} 4f^{14} 5s^2 5p^6 5d^2 6s^2$ belongs to

$\int \frac{dx}{\sqrt{x}(x+9)}$ is equal to

An ideal transformer has $100$ turns in the primary and $250$ turns in the secondary. The peak value of the $AC$ voltage in the primary is $28\ V$. The $r.m.s.$ secondary voltage is nearest to $....V$.

Given in the figure are two blocks $A$ and $B$ of weight $20 \, N$ and $100 \, N$,respectively. These are being pressed against a wall by a force $F$ such that the system does not slide as shown. If the coefficient of friction between the blocks is $0.1$ and between block $B$ and the wall is $0.15$,the frictional force applied by the wall on block $B$ is ........ $N$.

Select the incorrect pair: