Machine-translated by Google. Questions are authored in English.
Top

Discussion

A uniformly charged cube of side one cm having surface charge density of 8.85 μC cm-2is placed inside a hollow metal sphere. The total flux emerging out of the sphere in Nm2C-1 is (ε0 = 8.85 x 10-12 C2N-1m-2)

  • A.\(8.85 \times 10^{6}\)
  • B.\(12 \times 10^{6}\)
  • C.\(19.7 \times 10^{6}\)
  • D.\(3 \times 10^{6}\)
  • E.\(6 \times 10^{6}\)

Answer: E

The flux is \(6 \times 10^{6}\) N m2 C-1.

The cube has 6 faces of 1 cm2, so its total charge is \(q = 8.85\ \mu\text{C cm}^{-2} \times 6\ \text{cm}^{2} = 53.1\ \mu\text{C}\). The uncharged metal sphere does not change the net enclosed charge, so by Gauss's law:

\[ \begin{aligned} \Phi &= \frac{q}{\varepsilon_0} = \frac{53.1 \times 10^{-6}}{8.85 \times 10^{-12}} \\ &= 6 \times 10^{6} \end{aligned} \]

Using one face only gives \(1 \times 10^{6}\); the other values do not follow from the cube's six faces.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.