Physics Midterm part 5

Question 1

Electromagnetism

Answer 1

Branch of physics that deals with the relationship between electricity and magnetism. A magnetic field always surrounds a conductor in which electric charge is flowing

Question 2

John Fleming

Answer 2

Developed a series of hand rules to describe various electromagnetic relationships. Right hand rules are used with current flow and left hand are used with electron flow.

Question 3

Helix

Answer 3

Coil in an electromagnet. When connected to electric current, magnetic flux density will increase, and north + south poles will appear around coil.

Question 4

Solenoid

Answer 4

When a helix is connected to electric current, magnetic flux density will increase, and north + south poles will appear around coil.

Question 5

Electromagent

Answer 5

Adding a ferromagnetic core to increased magnetic flux density

Question 6

Electromagnetic induction

Answer 6

Using a electric current to create a magnetic field and using a magnetic field to create an electric current. Discovered by Michael Farady in 1831

Question 7

Faraday’s 1st law of electromagnetism

Answer 7

Whenever a conductor moves through a magnetic field, a voltage will be induced in the conductor.

Question 8

3 ways to produce motion in Faraday’s 1st law

Answer 8

1. Move the conductor
2. Move the magnetic lines of force
3. Vary the magnetic field strength

Question 9

4 things that affect amount of voltage created during elecromagnetic induction

Answer 9

1. Strength of the magnetic field - The stronger the magnetic field, the greater the voltage induced because there are more lines of force
2. Speed of motion between the lines of force and conductor - The greater the speed, the greater the voltage
3. The amount of conductor in the magnetic field - The greater the amount of conductor, the greater the voltage induced.
4. The angle between the conductor and magnetic lines of force - The greatest voltage is created when the conductor passes at 90 degree angle to the lines of force while no voltage is produced when the conductor runs parallel to the lines of force.

Question 10

Electric generator or dynamo

Answer 10

A device that converts mechanical energy into electrical energy using the principle of electromagnetic induction

Question 11

2 main parts to an electric geenrator

Answer 11

1. magnets - to create a magnetic field
2. Armature - a coil of wire that will be mechanically rotated in the magnetic field

Question 12

Electric Motor

Answer 12

A device that converts electrical energy into mechanical energy using electromagnetic induction

Question 13

2 main parts of an induction motor

Answer 13

1. Stator - this is a series of electromagnets that are equally spaced around a metal ring
   2.Rotor - located inside of the induction motor, made of copper with iron bars equally spaced throughout

Question 14

Lenz;s 2nd law of electromagnetism

Answer 14

States that the electrons will flow in the same direction as the action that induces it

Question 15

Proton mass and rest energy

Answer 15

1.672x10^-27, 938 MeV

Question 15

Neutron mass and rest energy

Answer 15

1.675x10^-27, 940 MeV

Question 16

Electron mass and rest energy

Answer 16

9.11x10^-31, 0.511 MeV

Question 17

Electron binding energy dependent on 2 factors

Answer 17

1. Distance of electrons to nucleus - the closer the orbit to nucleus the greater the electron binding energy
2. Number of protons in nucleus - The greater the number the greater the binding energy

Question 18

Photons

Answer 18

the force carriers of the electromagnetic field

Question 19

W & Z bosons

Answer 19

The force carriers which mediate the weak force

Question 20

Gluons

Answer 20

fundamental force carriers underlying the strong force

Question 21

Higgs bosons

Answer 21

give W and Z bosons mass via the Higgs mechanism.

Question 22

Protons are made up of

Answer 22

2 up and 1 down quark

Question 23

Neutrons are made up of

Answer 23

2 down and 1 up quark

Question 24

Up quakrs

Answer 24

Have a charge of +2/3

Question 25

Down quarks

Answer 25

Have a charge of -1/3