A point charge q is placed inside a cavity within a conductor. The conductor is electrically neutral and is isolated . The total charge on the outer surface of the conductor must be ______.
举一反三
- Which of the following statements about a conductor in the static case is not true导体在静电平衡下表述不正确的是 A: The conductor must be at the same electric potential B: The surface of the conductor is an equi-potential surface等势面 C: There can be an electric field within the conductor导体内 D: There can be no net charge within the conductor体内无净电荷
- On the surface of a perfect conductor, the normal component of the electric displacement vector is A: continuous with the normal component of the electric displacement vector inside the conductor B: uncertain C: equal to the surface density of free charge on the conductor surface. D: equal to zero
- The magnentic field is generated by A: voltage applied to the conductor B: current through the conductor C: charge shifts D: permanent magnet
- There is no magnetic field in an ideal conductor, but there is a magnetic field inside because of the surface current。
- A spherical conducting shell has charge Q. A particle with charge q is placed at the center of the cavity. The charge on the inner surface of the shell and the charge on the outer surface of the shell, respectively, are: A: 0, Q B: q, Q −q C: Q, 0 D: −q, Q + q E: −q, 0