Electricity Quiz #1 Flashcards
1
Q
What is a static electric charge?
A
An imbalance between electrical charges on a material’s surface.
ex. positively charged body touches negatively charge door knob
2
Q
How is static charge produced?
A
- friction between 2 surfaces lead to a gain or loss of electrons
ex. feet on carpet
3
Q
What is an electroscope?
A
- 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
4
Q
What has an electric charge?
A
- An atom that has lost (Positive) or gained (Negative) electrons
5
Q
How are charges on objects created?
A
-
6
Q
What is a conductor and insulator?
A
- a conductor (metal) is used to transfer charge between objects
ex. wires - an insulator stops the flow of electrons
ex. rubber, plastic covering wires
7
Q
What are the rules of static electricity?
A
- objects with like charges repel one another
- objects with opposite charges attract one another
- charged objects attract neutral objects
8
Q
What are some rules of generating electricity?
A
- energy is neither created nor destroyed
- it is transformed from one kind of energy into another
9
Q
What is kinetic and potential energy?
A
- 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
10
Q
What is chemical energy
A
- 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
11
Q
Kinetic energy –> Electrical energy
A
- 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)
12
Q
What is solar energy?
A
- energy carried by sun
- fossil fuels and biomass are result of plant capturing sun’s energy
13
Q
What is nuclear energy?
A
- 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
14
Q
What is thermal energy?
A
- 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
15
Q
How do solar panels work?
A
- 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%
16
Q
How is it like in a nuclear power plant?
A
- 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
17
Q
What is an electrochemical cell?
A
- devices that convert chemical energy into electrical energy
- when two or more cells are combined together, we call this a battery
18
Q
What is the structure of an electrochemical cell
A
- 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
19
Q
What is a circuit?
A
- a path for the electrons to follow
20
Q
What are the 4 components necessary for an electrochemical cell to function?
A
- 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
21
Q
What is work?
A
- moving something by applying a force (push, pull) over a distance
22
Q
What is energy?
A
- ability to move something by applying force
23
Q
What is electric potential energy?
A
- 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
24
Q
How is energy like a staircase?
A
- 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
25
Q
What is a coulomb?
A
- A unit of which charge is measured
- one coulomb = 6.24 x 10^18
26
Q
How is current measured?
A
- Current = Amperes (Amps)
- Amps = 1 coulomb per second
27
Q
What is a voltmeter?
A
- a device that measures the amount of electrical potential energy (Volts) between 2 locations of charge separation
28
Q
What is electric current?
A
- 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
29
Q
What is conventional current?
A
- 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
30
Q
What is electrical resistance, and what is it measured with?
A
- 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
31
Q
What are the 4 basic components in a circuit?
A
- 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
32
Q
What are the rules to follow when drawing circuits?
A
- 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
33
Q
What is the symbol for voltmeter, motor, light bulb, and ammeter?
A
- circles with v, m, filament, and a
34
Q
What is the symbol for conducting wire, electrochemical cell, battery, resistor, open switch, and closed switch?
A
line, 1 cell line, 1+ cell line, squiggle line, open line, closed line
