$A$ convex lens is made up of three different materials as shown in the figure. For a point object placed on its axis,the number of images formed is:

In $chloroethane$,the carbon bearing halogen is bonded to $...$ hydrogen $(s)$. It is called $......$ alkyl halide.

Which of the following reagents reacts differently with $HCHO$,$CH_3CHO$,and $CH_3COCH_3$?

The relation between the current $i$ (in ampere) in a conductor and the time $t$ (in second) is $i=12t+9t^2$. The charge passing through the conductor between the times $t=2 \ s$ and $t=10 \ s$ is (in $C$)

The product of the lengths of the perpendiculars drawn from the point $(-1, 5)$ to the pair of lines $2x^2 - xy - 3y^2 + 6x + y + 4 = 0$ is

Which of the following national parks is not a habitat for tigers?