Male gametes are flagellated in

Which of the following substances imparts a green color to the burner flame?

The incentre of the triangle formed by the lines $x+y=1$,$x=1$,and $y=1$ is

Which of the following is used for making optical instruments?

$A$ parallel plate capacitor of capacity $C_0$ is charged to a potential $V_0$. $(i)$ The energy stored in the capacitor when the battery is disconnected and the plate separation is doubled is $E_1$. (ii) The energy stored in the capacitor when the charging battery is kept connected and the separation between the capacitor plates is doubled is $E_2$. Then,the value of $E_1 / E_2$ is:

Columella auris is a modified