Electricity and Magnetism Midterm Exam

Electric charge occurs only in separate parcels

• of 1.6 x 10^-19 C

• of 1.0 C

• whose value is proportional to the mass of the mass of the particle carrying the charge

• that are different for positive and negative particles

The electrons in an atom

• are permanently bound to it

• have more mass than the nucleus

• are some distance from the nucleus

• may have positive or negative charges

The electric force between two protons

• is weaker than the gravitational force between them

• is equal to the gravitational force between them

• is stronger than the gravitational force between them

• depending on the distance between the protons

The magnitude of the electric field in the region between two parallel oppositely charged metal plates is

• Zero

• uniform throughout the region

• greatest near the positive plate

• greatest near the negative plate

The same potential differences is used to accelerate a proton and an electron. Afterward

• the proton has the higher velocity

• the electron has the higher velocity

• the proton has more KE

• the electron has more KE

A system of two charges has a positive potential energy. This signifies that

• both charges are positive

• both charges are negative

• both charges are positive or both are negative

• one charge is positive and the other is negative

An electron and a proton are accelerated through the same potential difference

• The electron has the greater KE

• The proton has the greater KE

• The electron has the greater speed

• The proton has the greater speed

The electron volt is a unit of

• charge

• potential difference

• momentum

• energy

An insulator material is one

• whose electrons are firmly bound in place

• which has no free electrons

• in which some electrons are free to move about

• which has too many electrons

A rod with an unknown charge attracts a plastic ball. Which one or more of the following might describe them?

i. the rod is positive and the ball is negative

ii. the rod is negative and the ball is positive

iii. the rod is positive and the ball is uncharged the rod is negative and the ball is uncharged

• i

• i & ii

• i, ii & iii

• i, ii, iii & iv