Electrostatics and Electrical Concepts Exam Review

A series of flashcards covering key concepts in electrostatics, pertaining to various topics from charges, forces, to conductors and insulators.

What do we call a material that allows electric charges to flow through it?

A conductor.

What is the charge-to-mass ratio of an electron?

1.76 imes 10^{-11} ext{ C/kg}.

If a positively charged glass rod attracts object X, what can we say about the net charge of object X?

It may be zero or negative.

What happens to the electric force between two stationary particles if each charge is doubled?

The electric force will quadruple.

What do electrostatic field lines do?

They start at positive charges and can only end at negative charges or infinity.

What will happen to a conductor when a positive charge is brought near it and then grounded?

The conductor will be negatively charged after the positive charge is removed.

If a metal sphere has a net negative charge of 1.1 imes 10^{-6} coulombs, approximately how many more electrons than protons does it have?

6.9 imes 10^{12} more electrons than protons.

What happens when a neutral metal sphere is charged by contact with a positively charged rod?

The sphere loses electrons.

What is the net charge of an object possessing an excess of 6.0 imes 10^{6} electrons?

-9.6 imes 10^{-13} ext{ C}.

If a negatively charged plastic comb is attracted to a small piece of paper, what can be inferred about the charge on the paper?

It may be negative or neutral.

What charge could a particle have?

A particle could have charges like 0.8 imes 10^{-19} ext{ C}, 1.2 imes 10^{-19} ext{ C}, etc.

What is the charge of a neutron?

A neutron has no charge.

When identical charged spheres touch and are separated, what is the charge on the first sphere if it had an excess charge of +11 and the second had -3?

The charge of the first sphere will be +4.

What happens when a positively charged body touches a neutral body?

The neutral body will gain electrons.

How can a pith ball become charged?

By gaining or losing electrons.

What happens when two identical uncharged spheres A and B touch after A is charged with +q?

Sphere A will have a charge of +rac{q}{2} after separation.

If object A becomes positively charged when rubbed with object B, what charge does object B have?

Object B has gained electrons and become negatively charged.

When a wool cloth is rubbed against rubber and becomes positively charged, what does it lose?

It loses electrons.

What is equivalent to three elementary charges?

4.8 imes 10^{-19} ext{ C}.

How does the charge on a body change when it comes in contact with a neutral body?

The charge on the first body decreases.

How many electrons does a neutral atom of Carbon have if there are 6 protons?

It has 6 electrons.

What does the coulomb (C) measure?

The coulomb is a unit of electrical charge.

What happens to the leaves of an electroscope when a positively charged rod is brought near it?

The leaves diverge due to positive charges being repelled.

What indicates that charges are distributed on an electroscope without touching it?

Induced charge distribution occurs.

If solid A acquires a negative charge after rubbing with another solid, what happens to solid B?

Solid B must have lost electrons and acquired a net positive charge.

When two negatively charged spheres touch and are separated, what will result for the first sphere?

The charge on sphere A will be -3 units.

What particles in the nucleus of an atom are positively charged?

Protons.

How does the charge of a charged rod and a cloth relate when rubbed together?

If the rod acquires a charge of +1.0 imes 10^{-6} ext{ C}, the cloth acquires -1.0 imes 10^{-6} ext{ C}.

What charge is represented by an excess of 2.5 imes 10^{19} electrons?

The net charge is -4.0 ext{ C}.

What is the electrical force between two charges of 0.2 C and 0.4 C separated by 0.1 m?

This requires calculation using Coulomb's law.

How many electrons must be removed to give a positive charge of 8.0 imes 10^{-8} ext{ C}?

This is calculated using the charge of one electron.