Fields Multiple Choice

Question 1

Thanks to _____, we now have a way to explain how forces can be exerted remotely and how to visualize 3D fields.

Answer 1

Michael Faraday

Question 2

_____ is credited with first quantifying electric force

Answer 2

Charles Coulomb

Question 3

The _____ force is the only field to always attract

Answer 3

Gravitational

Question 4

Electric field lines

Answer 4

Intersect an object’s surface at right angles, never cross, get denser as the field gets stronger

Question 5

The _____ principle: Moving charges create magnetic fields

Answer 5

Oersted

Question 6

The angle that the Earth’s magnetic field lines intersect the surface is called _____

Answer 6

Inclination

Question 7

At atomic distances, the _____ field is the strongest

Answer 7

Electrostatic field

Question 8

_____ is credited with the discovery of the electron.

Answer 8

J.J. Thomson

Question 9

There are ______ electrons in 1 Coulomb of charge.

Answer 9

6.25 x 10^18

Question 10

The map of a gravitational field around a large mass can be directly determined with

Answer 10

a small test mass

Question 11

The difference in angle between geographical north and magnetic south is called ____

Answer 11

declination

Question 12

The force of attraction between two point charges is

Answer 12

Directly proportional to the product of their charges and inversely proportional to the distance squared between them

Question 13

The charge of a single electron or particle is; and was found by…..

Answer 13

Elementary charge of a single electron is 1.60 x 10^-19 C. Discovered by Robert Millikan

Question 14

When did we discover that materials have magnetic properties?

Answer 14

We have known since 2 500BC. Legend has it that Magnes from Northern Greece known as Magnesia noticed the nails in his sandals attracted the black rock beneath them.

Question 15

What were the rocks that stuck to Magnes’ sandals?

Answer 15

Iron oxide, lodestone

Question 16

If you break a magnet in half, you will never be able to create a magnet with only one pole called a ___

Answer 16

monopole

Question 17

Permanent magnets are often made from an alloy called _____

Answer 17

alnico

Question 18

Any material that is a magnet or can be magnetized is called a _______ material

Answer 18

Ferromagnetic

Question 19

The number of magnetic field lines passing through a surface is called _______

Answer 19

magnetic flux

Question 20

The flux per unit area is proportional to the _____ of the magnetic field

Answer 20

strength

Question 21

The units for magnetic strength are ______ named after _______

Answer 21

tesla, Nikola Tesla

Question 22

On a microscopic level, a magnet is made of groups of electrons called a _____

Answer 22

domain

Question 23

Who suggested that the earth was a giant magnet?

Answer 23

William Gerbert

Question 24

The strength of the Earth’s magnetic field is

Answer 24

5 x 10^-5 T

Question 25

Right Hand Rule #1

Answer 25

For any current carrying wire, you can find the direction of the magnetic field using the right hand rule. Grasp wire with your right and thumb pointing in direction of conventional current, the fingers of your hand point in direction of magnetic north.

Question 26

Right Hand Rule #2

Answer 26

A coil of wire that creates continuous series of loops along an empty core is called a solenoid. If a current runs through the loops, an electromagnet is formed. The direction can be determined with the second right hand rule. Grasping the coil with your hand hand fingers pointing in direction of current, your thumb will point in direction of north pole.

Question 27

Factors affecting the strength of an electromagnet

Answer 27

1. Increasing the current 2. Increasing the number of turns per unit length of the solenoid 3. Using a soft-iron core within the solenoid

Question 28

Right Hand Rule #3

Answer 28

The current carrying wire creates a magnetic field, so it will experience a force in the presence of another magnetic field. The direction of this force is found with the third right hand rule. Point fingers in direction of magnetic field. Point thumb in direction of conventional current flow. Palm faces the direction of the force.

Question 29

What is a field?

Answer 29

A region of space characterized by a physical property which has a determinable value at every point in that region.