Static Fields: Fall-2025
HW 07 Practice: Due W4 D3

  1. Flux through a Cylinder
       
    1. What do you think will be the flux through the cylindrical surface that is placed as shown in the constant vector field in the first figure?
    2. What if the cylinder is placed upright, as shown in the second figure? Explain.
  2. Flux I Find the flux of \(\boldsymbol{\vec F} =x\,\boldsymbol{\hat x}+y\,\boldsymbol{\hat y} +z\,\boldsymbol{\hat z}\) out of a closed cylinder of radius 2 centered on the \(z\)-axis, with \(-3\le z\le3\).
  3. Flux II Find the flux of \(\boldsymbol{\vec F}=z^2\,\boldsymbol{\hat z}\) through the upper hemisphere of the sphere \(x^2+y^2+z^2=25\), oriented away from the origin.
  4. Flux III Let \(\boldsymbol{\vec H} = (e^{xy}+3z+5)\,\boldsymbol{\hat x} + (e^{xy}+5z+3)\,\boldsymbol{\hat y} + (3z+e^{xy})\,\boldsymbol{\hat z}\). Calculate the flux of \(\boldsymbol{\vec H}\) through the square of side \(2\) with one vertex at the origin, one edge along the positive \(y\)-axis, one edge in the \(xz\)-plane with \(x>0\), \(z>0\), and with normal \(\boldsymbol{\hat n}=\boldsymbol{\hat x}-\boldsymbol{\hat z}\).
  5. Flux through a Plane Find the upward pointing flux of the vector field \(\boldsymbol{\vec{H}}=2z\,\boldsymbol{\hat{x}} +\frac{1}{x^2+1}\boldsymbol{\hat{y}}+(3+2z)\boldsymbol{\hat{z}}\) through the rectangle \(R\) with one edge along the \(y\) axis and the other in the \(xz\)-plane along the line \(z=x\), with \(0\le y\le2\) and \(0\le x\le3\).
  6. Gauss's Law for a Rod inside a Cube Consider a thin charged rod of length \(L\) standing along the \(z\)-axis with the bottom end on the \(x,y\)-plane. The charge density \(\lambda_0\) is constant. Find the total flux of the electric field through a closed cubical surface with sides of length \(3L\) centered at the origin.
  7. Volume Charge Density

    Consider the volume charge density: \begin{equation*} \rho (x,y,z)=c\,\delta (x-3) \end{equation*}

    1. Describe in words how this charge is distributed in space.
    2. What are the dimensions of the constant \(c\)?