Charges and the electric field

Question 1

A sphere of radius r has a net charge +Q distributed uniformly through its volume.  Which material could the sphere be made of?
Copper 
Gold
Superconducting 
aluminium
Plastic

Answer 1

Plastic

Question 2

Materials in which the electrons are bound very tightly to the nuclei are referred to as?
conductors
insulators
semi-conductors
solid

Answer 2

Insulators

Question 3

A positively charged rod,A, is brought close to (but not touching) one end of a neutral conducting rod,B. If a positive charge q is brought close to the other end of rod B (opposite the side with rod A), what force will q feel?
A force attracting it to rod B
A force repelling it from rod B
No force since rod B is neutral

Answer 3

A force repelling it from rod B

Question 4

Two point charges of equal magnitude but unknown sign are placed close to each other.The force between them will be: 
Repulsive
Attractive
Zero
Not enough information to answer

Answer 4

Not enough info

Question 5

What happens when a molecule with a permanent electric dipole moment is placed in an electric field?
The molecule gains an additional induced dipole
Torque generated from the electric field aligns the molecule’s dipole with the external field
Nothing happens

Answer 5

Torque generated from the electric field aligns the molecule’s dipole with the external field

Question 6

Which particles are responsible for excess charge in material?
protons
electrons
neutrons
photons

Answer 6

Electrons

Question 7

A positively charged sphere is brought near a neutral conducting metallic rod.
A. There is no electric field in the rod
B. The total electric field in the rod is to the right
C. The total electric field in the rod is to the left

Answer 7

There is no electric field in the rod

Question 8

An electric dipole is made from two (opposite) charges with magnitude,Q, separated by a distance,l, and placed such that the centre of the dipole is at the origin of a coordinate system. At a distance R&raquo_space; l from the origin, what can be said of the magnitude of the electric field from the dipole?
It is weaker than that from a single positive charge Q placed at the origin
It is stronger than that from a single positive charge Q placed at the origin
It is zero, because no net charge is enclosed by a Gaussian sphere of radius R
It is the same strength as the field from a single charge 2Q placed at the origin

Answer 8

It is weaker than that from a single positive charge Q placed at the origin(Correct)