Physics
Conductors and Insulators
Practice questions
How is a positive charge placed in the cavity of a neutral conductor balanced so that the electric field inside the conducting material remains zero?If a negative charge inside the cavity of a neutral conductor is not touching the conductor what will be the total charge on the outer surface?Why can an external charge not produce a field inside an empty cavity of a closed conducting shell?If the electric field inside a conductor is zero is it impossible to have electric field outside it?Why must the component of electric field parallel to a conductor surface be zero in electrostatic equilibrium?The electric field just outside a conductor is perpendicular to its surface. Which conclusion follows from this fact?Why does surface charge density vary over a conductor having regions with different curvatures?Why is ionisation of air more likely near a sharp conducting tip?Charge spreads uniformly on an isolated spherical conductor but not necessarily on an irregular conductor. What is the main reason?Why does the surface charge distribution change when an external charge is brought near an isolated conductor?Why does a positive effect appear at the far end of a neutral conductor when a positively charged rod is brought near it?Why does a negative effect appear at the far end of a neutral conductor when a negatively charged rod is brought near it?Why does the net charge remain unchanged when induction occurs in a neutral conductor without contact or earthing?Why must earthing be removed before the external object is removed during charging by induction?Why can electrons move from Earth to an earthed conductor near a positively charged rod?Why can electrons go from an earthed conductor to earth near a negatively charged rod?A conductor is earthed. What does it mean that its potential becomes equal to Earth’s potential?Why can attraction occur in an insulator due to polarisation even if its net charge remains zero?How can induction in a conductor and polarisation in an insulator be distinguished at the microscopic level?A rubbed insulator does not spread charge over its whole surface. What is the deeper reason?