Electricity Quiz #1

Question 1

What is a static electric charge?

Answer 1

An imbalance between electrical charges on a material’s surface.
ex. positively charged body touches negatively charge door knob

Question 2

How is static charge produced?

Answer 2

• friction between 2 surfaces lead to a gain or loss of electrons
  ex. feet on carpet

Question 3

What is an electroscope?

Answer 3

• A device that detects charged objects
• It will show an attracting or repulsing action if a charged object is brought near
  ex. Pith ball on string moves closer or farther away from object depending on charge

Question 4

What has an electric charge?

Answer 4

• An atom that has lost (Positive) or gained (Negative) electrons

Question 5

How are charges on objects created?

Answer 5

-

Question 6

What is a conductor and insulator?

Answer 6

• a conductor (metal) is used to transfer charge between objects
  ex. wires
• an insulator stops the flow of electrons
  ex. rubber, plastic covering wires

Question 7

What are the rules of static electricity?

Answer 7

• objects with like charges repel one another
• objects with opposite charges attract one another
• charged objects attract neutral objects

Question 8

What are some rules of generating electricity?

Answer 8

• energy is neither created nor destroyed
• it is transformed from one kind of energy into another

Question 9

What is kinetic and potential energy?

Answer 9

• k.e. is the energy of motion
• p.e is the energy stored in a system/object due to its position or condition
• together, these are mechanical energy

Question 10

What is chemical energy

Answer 10

• energy stored in bonds within molecules
• energy is released when a chemical reaction occurs
• mitochondria converts glucose molecules to energy useful for cell by getting energy from the bonds
• batteries use chemical energy by storing molecules and ions in their structures allowing electrons to transfer between them
• fossil fuels (coal, oil, and natural gas) store chemical energy

Question 11

Kinetic energy –> Electrical energy

Answer 11

• steam, water, or wind spins turbine and shaft
• the shaft connects the turbine to the generator
• the kinetic energy of the shaft is converted to electrical energy in the generator
• As the shaft turns the wire loop/coil in the generator, there is a magnet surrounding it and electrons flow in the wire (current)

Question 12

What is solar energy?

Answer 12

• energy carried by sun
• fossil fuels and biomass are result of plant capturing sun’s energy

Question 13

What is nuclear energy?

Answer 13

• nuclear fusion (smaller atoms collide to form new atoms) happens in stars to generate energy
• nuclear fission (larger, unstable atoms split) happens in reactors on earth to generate energy

Question 14

What is thermal energy?

Answer 14

• rapid motion of particles that make up an object (KMT, heat)
• It can come from nuclear reactions, earth’s interior…etc.
• volcanoes and hot springs form steam to move turbines

Question 15

How do solar panels work?

Answer 15

• panels are made of silicon sandwiched between different conductive layers and is connected to its neighbours by 4 chemical bonds
• The movement of electrons in solar cells make a positive and a negative side of the cell
• electrons naturally push to one side of the cell to be collected into thin wires.
• the most efficient solar cell right now is 46%

Question 16

How is it like in a nuclear power plant?

Answer 16

• Uranium atoms are split into smaller atoms by a neutron (this is called a fission)
• The unstable uranium separates to form 2 smaller atoms & 3 neutrons that continue the chain reaction of hitting other uranium atoms
• water is required to slow the neutrons and cool the reactor to prevent a nuclear explosion

Question 17

What is an electrochemical cell?

Answer 17

• devices that convert chemical energy into electrical energy
• when two or more cells are combined together, we call this a battery

Question 18

What is the structure of an electrochemical cell

Answer 18

• the chemical energy isolates the negative terminal and positive terminal of the cell
• when a battery is connected to a device using wires, the electrons travel from the negative terminal –> device –> positive terminal to complete the circuit

Question 19

What is a circuit?

Answer 19

• a path for the electrons to follow

Question 20

What are the 4 components necessary for an electrochemical cell to function?

Answer 20

• negative terminal that accepts electrons
• positive terminal that gives up electrons
• electrolyte that removes electrons from the positive terminal by chemical reaction
• separator that keeps electrons separate from the positive terminal

Question 21

What is work?

Answer 21

• moving something by applying a force (push, pull) over a distance

Question 22

What is energy?

Answer 22

• ability to move something by applying force

Question 23

What is electric potential energy?

Answer 23

• electrical energy stored in a battery
• electrons have Electrical potential energy
• it depends on charge amount and separation = volts
  ex. chemical reaction in battery provides the electron with a push = charge separation which leads to chemical potential energy
  -volts

Question 24

How is energy like a staircase?

Answer 24

• bottom of stairs no P.E.
• top of stairs lots of P.E.
• P.E. of person on stairs = height of stairs and mass of person
• going through the circuit, the e- will use the electrical P.E. that has been given to it in the battery

Question 25

What is a coulomb?

Answer 25

• A unit of which charge is measured
• one coulomb = 6.24 x 10^18

Question 26

How is current measured?

Answer 26

• Current = Amperes (Amps)
• Amps = 1 coulomb per second

Question 27

What is a voltmeter?

Answer 27

• a device that measures the amount of electrical potential energy (Volts) between 2 locations of charge separation

Question 28

What is electric current?

Answer 28

• the amount of charge (measured in coulombs) passing through one point in a conductor every second
• measured in units called amperes or amps (A)
• ammeter is a device used to measure current in a circuit
• often referred to as flow of electrons
  ex. phone charger uses/draws 1.5 A of current

Question 29

What is conventional current?

Answer 29

• original idea before discovery of electrons was that current flowed from positive to negative and the positive particle was moving
• we still use the term conventional current to describe flow from positive to negative because it is so entrenched in our past understanding

Question 30

What is electrical resistance, and what is it measured with?

Answer 30

• slows the flow of electrons and converts electrical energy into other forms of energy (heat, light, sound, etc.).
• measured in units called ohms using an ohmmeter
• ohmmeter applies a voltage and measures the current in the circuit

Question 31

What are the 4 basic components in a circuit?

Answer 31

• chemical cells as a source of electrical energy (batteries)
• conductor as a wire for electrons to flow through
• load as a device that transforms electrical energy into other forms of energy
  ex. light bulb, buzzer, heater, motor
• switch to turn circuit on or off

Question 32

What are the rules to follow when drawing circuits?

Answer 32

• draw with a ruler
• connect wires and leads should be straight with 90 degree corners
• finished drawings should be square or rectangle
• try not to overlay conductor lines
• use specific symbols to represent the components

Question 33

What is the symbol for voltmeter, motor, light bulb, and ammeter?

Answer 33

• circles with v, m, filament, and a

Question 34

What is the symbol for conducting wire, electrochemical cell, battery, resistor, open switch, and closed switch?

Answer 34

line, 1 cell line, 1+ cell line, squiggle line, open line, closed line