Which of the following structures corresponds to the product expected when an excess of $C_6H_6$ reacts with $CH_2Cl_2$ in the presence of anhydrous $AlCl_3$?

The radius of gyration of a disc of mass $50\,g$ and radius $2.5\,cm$,about an axis passing through its centre of gravity and perpendicular to the plane,is ....... $cm$.

Crystalline sodium chloride is an insulator of electricity because $......$

What is obtained when calcium carbide reacts with heavy water?

$A$ linear charge having linear charge density $\lambda$ penetrates a cube diagonally and then it penetrates a sphere diametrically as shown. What will be the ratio of flux coming out of the cube and the sphere?

If the roots of the equation $x^2+px+q=0$ are $\alpha$ and $\beta$,and the roots of the equation $x^2-rx+s=0$ are $\alpha^4$ and $\beta^4$,then the roots of the equation $x^2-4qx+2q^2-r=0$ will be