What will be the angular width of the central maxima in Fraunhofer diffraction when light of wavelength $6000 \, \mathring{A}$ is used and the slit width is $12 \times 10^{-5} \, cm$? (in $rad$)

Currents flowing in each of the following circuits $A$ and $B$ respectively are:

The pole of the straight line $x+4y=4$ with respect to the ellipse $x^2+4y^2=4$ is

$A$ plano-convex lens is made of glass with a refractive index of $1.5$. The radius of curvature of its convex surface is $R$. What is its focal length?

Let $\overrightarrow{a}=a_1 \hat{i}+a_2 \hat{j}+a_3 \hat{k}$.
Assertion $(A)$: The identity $|\overrightarrow{a} \times \hat{i}|^2+|\overrightarrow{a} \times \hat{j}|^2+|\overrightarrow{a} \times \hat{k}|^2=2|\overrightarrow{a}|^2$ holds for $\overrightarrow{a}$.
Reason $(R)$: $\overrightarrow{a} \times \hat{i}=a_3 \hat{j}-a_2 \hat{k}$,$\overrightarrow{a} \times \hat{j}=a_1 \hat{k}-a_3 \hat{i}$,and $\overrightarrow{a} \times \hat{k}=a_2 \hat{i}-a_1 \hat{j}$.
Which of the following is correct?

Which organelle of the cell is responsible for the synthesis of steroids?