What is the molecular formula of the product formed when benzene is reacted with ethyl chloride in the presence of anhydrous aluminium chloride?

The maximum value of $x^4 e^{-x^2}$ is

If the maximum velocity with which an electron can be emitted from a photocell is $4 \times 10^8 \,cm/sec$,the stopping potential is ............ $V$ (mass of electron $= 9 \times 10^{-31} \,kg$).

For a normal eye,the cornea of the eye provides a converging power of $40 \ D$ and the least converging power of the eye lens behind the cornea is $20 \ D$. Using this information,the distance between the retina and the cornea-eye lens can be estimated to be ......... $cm$.

In the environment,ozone is known for its

If $(a+bx)^{-3} = \frac{1}{27} + \frac{1}{3}x + \dots$,then the ordered pair $(a, b)$ equals to