Which of the following pairs is incorrect?

The resultant gate and its Boolean expression in the given circuit is

$A$ parallel beam of white light falls on a convex lens. Images of blue,red,and green light are formed on the other side of the lens at distances $x, y,$ and $z$ respectively from the pole of the lens. Then:

The self-inductance of a choke coil is $10 \, mH$. When it is connected to a $10 \, V$ $DC$ source,the power loss is $20 \, W$. When it is connected to a $10 \, V$ $AC$ source,the power loss is $10 \, W$. The frequency of the $AC$ source is ....... $Hz$.

Which polymer is used as a lubricant and an electrical insulator?

$\left|\begin{array}{lll}24 & 25 & 26 \\ 25 & 26 & 27 \\ 26 & 27 & 27\end{array}\right|$ is equal to