Physics
Conductors and Insulators
Practice questions
Why is the tip of a lightning protection rod often made pointed?A conductor has a cavity and a charge is placed in the cavity. What is required for the field inside the conducting material to remain zero?Why does charge produced by rubbing on an insulator not immediately spread over the whole surface like it does on a conductor?Which is the most appropriate reason why the electric field is zero within the conducting material in electrostatic equilibrium?Why would electrostatic equilibrium be impossible if potential difference remains inside a conductor?Why does excess charge given to an isolated solid conductor reside on its outer surface in electrostatic equilibrium?A point charge \(+q\) is placed inside a closed cavity of a neutral conductor without touching the conductor. What is the total induced charge on the inner surface of the conductor?An isolated neutral conductor has a cavity. If a charge +q is placed inside the cavity without touching its wall, what is the total charge on the outer surface of the conductor?If the charge in a cavity is positive and the conductor is earthed which statement about charge on the outer surface is correct?Why is the electric field just outside a conductor surface perpendicular to the surface?What will happen if tangential electric field on a conductor surface is not zero?The magnitude of electric field just outside a conductor surface is mainly related to which local quantity?At a point on the surface of a conductor in electrostatic equilibrium in vacuum, the magnitude of surface charge density | σ | is high. Which statement is correct for the magnitude of the electric field just outside the surface at that point?Why is electric discharge more likely from a charged conductor with a sharp point?A charged, isolated spherical conductor is in electrostatic equilibrium, with no external electric field or nearby charged object. What is the main reason its surface charge distribution is uniform?Why can surface charge distribution become non-uniform when an external charge is brought near a spherical conductor?A positively charged rod is brought near an isolated neutral conductor without touching it. What are the induced charges on the nearer and farther surfaces, and what is the conductor’s net charge?If a neutral conductor is placed near a negatively charged rod what effects appear at the near and far ends?If a charged rod is only brought near a conductor and the conductor is neither touched nor earthed what is the net charge of the conductor?What is the role of earthing in actual charging by induction?