# Electrostats

**Electricity and Magnetism**Level 5

Consider a horizontal charged disk with center \(O\) and having surface charge density \(\sigma\), and radius \(R\),
Consider a vertical rectangle of dimensions \(2a \times 2h\), which cuts the disk at a distance \(a\) from its center, such that half of rectangle lies below the disk and half of it lies above the disk.Use \(a << R\) to find the value of flux of electric field in \( N m^2 C^{-1} \) through the rectangle **to the nearest integer**. The top view is shown below:

**Details and assumptions**

\(\sigma = 1.05 \times 10^{-4} Cm^{-2}\)

\( R = 3m \)

\( a = 2 mm\)

\( h = 1m\)