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Ideal sources | Circuit analysis | Electrical engineering | Khan Academy

Video vocabulary

how

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US / haʊ /

UK / haʊ /

A1
  • adjecitve
  • To what degree? in what amount?
  • adverb
  • (Used to explain the way to do something)
  • exclamation
  • For what purpose or reason?
  • (Used to ask someone or something's condition)

kind

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US / kaɪnd /

UK / kaɪnd /

A1
  • adjecitve
  • In a caring and helpful manner
  • friendly and considerate
  • noun
  • One type of thing

also

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US / 'ɔ:lsəʊ /

UK / ˈɔlso /

A1
  • adverb
  • In addition; too; in a similar way

this

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US / ðɪs /

UK / ðɪs /

A1
  • adjecitve
  • Used to indicate something already been discussed
  • Used to indicate something happening around now
  • adverb
  • An indication by a physical motion or gesture
  • A specific amount of
  • determiner
  • Person, thing, or idea near you
  • pronoun
  • Person, thing that has already been discussed

the

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US / ðə /

UK / ðə /

A1
  • article
  • Used to refer to something already mentioned
  • Used to show there is only one of something
  • determiner
  • Used to describe all of a family

terminal

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US / 'tɜ:mɪnl /

UK / ˈtɚmənəl /

A2
  • adjecitve
  • (Of an illness, etc.) likely to lead to death
  • noun
  • Final stop or station for a bus, train or plane
  • Place where trips end or begin, like a train stop
  • other
  • End part of some structure or concept

circuit

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US / ˈsɜ:kɪt /

UK / ˈsɜ:rkɪt /

B1
  • noun
  • An area where cars race in a circle
  • Route for journey all the way around a place
  • Series of events moving from place to place
  • other
  • Electronic equipment consisting of switches
  • verb
  • To complete a journey all the way round an area

demand

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US / dɪ'mɑ:nd /

UK / dɪˈmænd /

A2
  • noun
  • Desire customers have to buy product, service
  • A strong request for someone to do something
  • verb
  • To strongly request someone to do something

power

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US / 'paʊə(r) /

UK / ˈpaʊɚ /

A1
  • noun
  • Legal or official right to perform certain actions
  • Ability to move forcefully and quickly
  • Energy of something (e.g. electricity or fuel)
  • Mathematical way to multiply a number
  • Condition of being in political control
  • Physical force, energy, and strength
  • verb
  • To give energy to something, e.g. by electricity
  • To move something forcefully and quickly

one

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US / wʌn /

UK / wʌn /

A1
  • pronoun
  • You; we; people in general; someone
  • The thing or person previously referred to
  • adjecitve
  • Used to refer to people generally
  • Being a strong example of (something mentioned)
  • number
  • Number 1

other

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US / 'ʌðə(r) /

UK / ˈʌðər /

A1
  • adjecitve
  • A thing different from that mentioned
  • determiner
  • (Something) else; not the first (one)
  • pronoun
  • Being the one and only thing of that category

into

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US / 'ɪntə /

UK / ˈɪntu /

A1
  • preposition
  • Moving or going inside something
  • In the same direction as; in the direction of
  • So as to become; taking the state of

indication

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US / ˌɪndɪˈkeɪʃn /

UK / ˌɪndɪˈkeʃən /

A2
  • noun
  • Something showing something exists or will happen

what

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US / wɒt /

UK / hwɑt, hwʌt, wɔt, wʌt,hwət, wət /

A1
  • pronoun
  • Thing or things that; the same kind as
  • Used to emphasize something you are about to say
  • adjecitve
  • Used to refer to a particular amount, or number
  • Used to place emphasis on a particular quality
  • adverb
  • To a certain degree
  • determiner
  • Question words used for asking for information
  • exclamation
  • Used to express excitement, shock, or surprise
  • Used to ask people to repeat something they said

that

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US / ðæt /

UK / ðæt, ðət /

A1
  • adjecitve
  • The person or thing being talked about
  • Used to identify something both the speakers know
  • adverb
  • Used to reinforce adjectives and adverbs
  • To such a degree
  • conjunction
  • Used to connect a noun clause
  • Used to introduce an adverbial clause
  • Used to introduce a noun clause
  • determiner
  • Used as a noun to refer to something
  • pronoun
  • Referring an object far away
  • Used to refer to the relative pronoun ‘which’

like

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US / laɪk /

UK / laɪk /

A1
  • adjecitve
  • Being equal in status or kind to something else
  • Similar; the same
  • adverb
  • For example
  • preposition
  • Used as a filler; used to ad emphasis
  • In a way similar to the way something is done
  • Such as; for example
  • verb
  • To want to
  • To find something pleasing; to prefer something

independent

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US / ˌɪndɪˈpendənt /

UK / ˌɪndɪˈpɛndənt /

A2
  • adjecitve
  • Making your own decisions; acting by yourself
  • noun
  • A person not connected to a political party

label

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US / 'leɪbl /

UK / ˈlebəl /

A2
  • noun
  • A (luxury) brand owned by a company
  • A word or term used to describe a person, thing
  • A piece of paper or material to identify something
  • verb
  • To use a term to describe, often negatively
  • To attach material to identify something

current

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US / 'kʌrənt /

UK / ˈkɚrənt, ˈkʌr- /

A2
  • adjecitve
  • Happening or being in the present time
  • noun
  • Electricity flowing through wires
  • Movement of water in a river, or air in the sky

about

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US / ə'baʊt /

UK / əˈbaʊt /

A1
  • adverb
  • To be ready to; going to
  • Nearly; approximately; roughly
  • Near; next to; close to
  • In every direction; in the area of
  • preposition
  • Concerning or of (a topic)

down

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US / daʊn /

UK / daʊn /

A1
  • adjecitve
  • Being sad, sick, or unhappy
  • Not operating, working, or functioning as expected
  • adverb
  • In a sitting or lying position
  • Towards or on the ground, floor, or bottom
  • Written or copied onto a piece of paper or book
  • noun
  • A period of play in American Football
  • The soft, smooth hairs that cover a bird's body
  • preposition
  • Along something's path, course, or direction
  • Going from a higher position to a lower position
  • verb
  • To eat or drink very quickly and without stopping

element

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US / 'elɪmənt /

UK / ˈɛləmənt /

A2
  • noun
  • Essential or particular part of something

type

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US / taɪp /

UK / taɪp /

A1
  • noun
  • Printed letters or blocks used for printing them
  • Group of things or people sharing common features
  • verb
  • To identify something belonging to a group
  • To write by touching keys on a keyboard

right

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US / raɪt /

UK / raɪt /

A1
  • adjecitve
  • Correct or true
  • The south side of you looking at the rising sun
  • adverb
  • Exactly in a place or time
  • Being appropriate for a particular event
  • In a straight or direct manner
  • noun
  • Something you are legally or morally allowed to do
  • Ideal of what is just and good
  • Political view based on conservatism
  • verb
  • To fix something previously wrong or unjust
  • To make upright, as a boat that has turned over

everywhere

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US / ˈevriweə(r) /

UK / ˈevriwer /

A1
  • adverb
  • Every place

positive

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US / ˈpɒzətɪv /

UK / ˈpɑzɪtɪv /

A2
  • adjecitve
  • Showing agreement or support for something
  • Being sure about something; knowing the truth
  • Having the charge produced by electrons
  • Being good or useful
  • Showing that a chemical is present in a test

constant

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US / 'kɒnstənt /

UK / ˈkɑnstənt /

A2
  • adjecitve
  • Happening frequently or without pause
  • noun
  • Thing that happens always or at a regular rate

voltage

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US / ˈvəʊltɪdʒ /

UK / ˈvoʊltɪdʒ /

B1
  • noun
  • Measured force of electricity

short

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US / ʃɔ:t /

UK / ʃɔrt /

A1
  • adverb
  • Less than what is needed
  • Suddenly stopping what you are saying or doing
  • verb
  • (Of electric circuit) to spark because faulty
  • adjecitve
  • Measuring a small distance
  • Happening for a small amount of time
  • Unfriendly or rude

for

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US / fə(r) /

UK / fɔr,fə /

A1
  • preposition
  • Used to show the purpose, or need of something

set

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US / set /

UK / sɛt /

A1
  • adjecitve
  • Prepared for something; ready
  • noun
  • Complete group of something
  • Place where a television show or movie is filmed
  • Group of games in a tennis match
  • Device that receives radio or television signals
  • verb
  • To make a clock state or ring at a particular time
  • To decide upon or choose something
  • To make something ready for use (e.g. table)
  • To decide on a price for something
  • To become hard (of glue, concrete etc.)
  • To be located in a specific place or time
  • To put (e.g. a vase) down carefully in a place
  • To put someone in a certain condition or state
  • (Of the sun) to go lower than the horizon

source

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US / sɔ:s /

UK / sɔrs, sors /

A2
  • adjecitve
  • Produces or provides what is wanted or needed
  • noun
  • Piece of information; a person giving information
  • Place from which something necessary comes
  • verb
  • To get, e.g. a raw material, from somewhere

special

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US / 'speʃl /

UK / ˈspɛʃəl /

A1
  • adjecitve
  • Being additional or extra
  • Different, better or greater than normal
  • noun
  • Heavily discounted sales item

depend

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US / dɪˈpend /

UK / dɪˈpend /

B1
  • verb
  • Be controlled or determined by (someone/something)

those

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US / ðəʊz /

UK / ðoz /

A1
  • determiner
  • The people or things we are talking about
  • pronoun
  • The objects far from the speaker

talk

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US / tɔ:k /

UK / tɔk /

A1
  • noun
  • Style of speaking
  • Discussion between two countries
  • Giving information in front of people; lecture
  • Saying things or ideas to someone with words
  • verb
  • To make a formal speech about something
  • To say things or ideas to someone with words

line

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US / laɪn /

UK / laɪn /

A1
  • noun
  • Border that divides two places or regions
  • Long crease in the skin, often from age
  • Mark that is long, straight and very thin
  • Row of words, letters or numbers that are written
  • Telephone connection
  • People waiting one behind the other; queue
  • Long thin wire, e.g. for electrical signal
  • verb
  • To put material along the inside of something

coordinate

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US / kəʊ'ɔ:dɪneɪt /

UK / ko'ɔrdəˈnet /

B1
  • noun
  • Point on a map defining a location e.g. 135N, 34W
  • verb
  • To match styles or colors that go well together
  • To cause body parts to move smoothly together
  • To make plans to meet a shared goal
  • To bring order and organization to something

with

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US / wɪð /

UK / wɪð, wɪθ /

A1
  • preposition
  • As an employee of a certain company
  • Against something or someone
  • By using something as a means
  • Due to; because of
  • Including
  • Possessing as a feature
  • Related to
  • (Of the manner/attitude by which you do something)
  • Used to express that people or things are together

have

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US / həv /

UK / hæv /

A1
  • verb
  • To drink, smoke, eat or use something
  • To experience the effects of something
  • To organize an event, or join in an activity
  • To own, possess, or hold something
  • To cause to happen or produce a particular effect

complete

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US / kəm'pli:t /

UK / kəmˈplit /

A1
  • adjecitve
  • Being finished; done; achieved
  • Being as perfect and as total as could be
  • verb
  • To finish or reach the end of doing something

could

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US / kəd /

UK / kʊd /

A1
  • other
  • Past form of 'can' to mean have ability
  • Used to ask for something politely, or to offer

way

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US / weɪ /

UK / we /

A1
  • adverb
  • Used to emphasize the amount of something
  • noun
  • Particular aspect of something being thought about
  • One of various choices that could be made
  • Particular existing condition or state
  • (Often long) distance or length of time
  • How something is done
  • Route to go to a place
  • Small street
  • Usual behavior, emotions or habits of someone

direction

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US / də'rekʃn /

UK / dɪˈrɛkʃən, daɪ- /

A2
  • noun
  • When someone tells people what to do
  • Describes the way you are going, e.g. North

they

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US / ðeɪ /

UK / ðe /

A1
  • pronoun
  • Two or more people, animals, or things

curve

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US / kə:v /

UK / kɚv /

A2
  • noun
  • Smooth rounded line that is not straight
  • verb
  • To make something bend into a rounded shape

build

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US / bɪld /

UK / bɪld /

A1
  • noun
  • Your physical shape; physique
  • verb
  • To establish e.g. a reputation, over time
  • To construct a house, office, factory

all

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US / ɔ:l /

UK / ɔl /

A1
  • adverb
  • Completely; totally
  • determiner
  • Being every one of something
  • pronoun
  • 100% of something; the complete amount

look

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US / lʊk /

UK / lʊk /

A1
  • noun
  • Person's beauty or physical attractiveness
  • Particular style of dress, clothes, or appearance
  • The way someone, something appears to be
  • Act of searching for or examining something
  • verb
  • To appear to be; seem

show

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US / ʃəʊ /

UK / ʃo /

A1
  • noun
  • False display of love, emotion or action
  • An event for displaying or promoting goods
  • Play, opera or theater production
  • Presentation that is broadcast on TV or radio
  • verb
  • To be easily seen or displayed
  • To display your emotions or feelings
  • To let someone see something; display
  • To explain or teach how something is done
  • To lead someone somewhere; point them to something
  • To prove something to be true, correct
  • To reveal or allow something to be seen

change

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US / tʃeɪndʒ /

UK / tʃendʒ /

A1
  • noun
  • Exchange of one set of clothes for another
  • Money in the form of coins instead of paper
  • Money returned after giving too much
  • Act of making or becoming something else
  • verb
  • To exchange one set of clothes for another
  • To exchange one kind of money for another
  • To replace something with another thing
  • To make or become something else
  • To go from one train, bus, etc. and go to another

point

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US / pɔɪnt /

UK / pɔɪnt /

A1
  • noun
  • An item to be discussed
  • Small spot or dot
  • Fact or detail
  • Feature of something
  • The size of the text on a page or screen
  • A certain time or stage in a process
  • Certain position in time or space
  • Idea or fact you try to convince people about
  • Measurement of scores in a game, sport
  • Sharp end of something, e.g. a pen or pin
  • verb
  • To face a certain direction, e.g. north
  • To indicate something with your finger to others

supply

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US / sə'plaɪ /

UK / səˈplaɪ /

A2
  • noun
  • Availability of products and services for use
  • Specific things needed to perform a certain task
  • verb
  • To give or sell goods to others for their use

here

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US / hɪə(r) /

UK / hɪr /

A1
  • adverb
  • In this place; at this location, position or time

plus

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US / plʌs /

UK / plʌs /

A2
  • noun
  • A benefit or advantage
  • preposition
  • In addition; add
  • In addition to; Indicates a number above
  • Having a value greater than zero

basic

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US / 'beɪsɪk /

UK / ˈbesɪk /

A1
  • adjecitve
  • At the most important or easiest (beginner) level

ideal

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US / aɪˈdi:əl /

UK / aɪˈdiəl, aɪˈdil /

A2
  • adjecitve
  • Exactly right; could not be better
  • Which is thought of as being perfect

always

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US / 'ɔ:lweɪz /

UK / ˈɔlwez,-wɪz,-wiz /

A1
  • adverb
  • For a very long time
  • At all times; in every situation
  • For ever

inside

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US / ˌɪn'saɪd /

UK / ɪnˈsaɪd, ˈɪnˌsaɪd /

A2
  • adjecitve
  • Being in something
  • Being in a building
  • adverb
  • Into a house; indoors
  • noun
  • Inner part or surface of something

convention

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US / kənˈvenʃn /

UK / kənˈvɛnʃən /

A2
  • adjecitve
  • Concerning a large formal assembly or meeting
  • noun
  • Official agreement between two or more countries
  • Large formal assembly, e.g. to make laws
  • Proper and widely accepted way of behaving

now

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US / naʊ /

UK / naʊ /

A1
  • adverb
  • At the present time or moment
  • Right away or in the next possible moment
  • Used to refer to something that just happened
  • Time between the present and a moment in the past
  • conjunction
  • Resulting from or because of something

equal

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US / 'i:kwəl /

UK / ˈikwəl /

A1
  • adjecitve
  • Same in shape, size, or number
  • verb
  • To add up or be the same as

same

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US / seɪm /

UK / sem /

A1
  • adjecitve
  • Being equal in quality and amount
  • Identical; not different
  • Not changing; constant

our

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US / 'aʊə(r) /

UK / aʊr /

A1
  • determiner
  • Belonging to us

not

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US / nɒt /

UK / nɑt /

A1
  • adverb
  • Word indicating the negative
  • (Used to form the negative of verbs)

would

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US / wʊd /

UK / wʊd /

A1
  • other
  • Used to indicate something imagined
  • Used to ask or request something politely
  • Verb used to indicate possibility, request etc.
  • Used to indicate a preference
  • Used to indicate a reaction
  • Indicates something that occurred repeatedly
  • Used to indicate willingness or ability to do

want

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US / wɔnt /

UK / wɑnt, wɔnt /

A1
  • noun
  • Something you desire or wish for
  • State or condition of poverty
  • verb
  • To desire or wish for something; hope for a thing

signal

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US / 'sɪɡnəl /

UK / ˈsɪɡnəl /

A2
  • adjecitve
  • Most important or most noticeable
  • noun
  • Movement of a hand or other means to send messages
  • Act/sound that tells people to do/start something
  • Road-side lights that direct traffic to go or stop
  • Sound and light waves carrying TV and radio data
  • verb
  • To be evidence/an indication something will happen
  • To make a noise or motion to tell someone to start

but

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US / bət /

UK / bʌt,bət /

A1
  • conjunction
  • Used before you say something different, opposite

deliver

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US / dɪ'lɪvə(r) /

UK / dɪˈlɪvɚ /

A2
  • verb
  • To give birth to a child; help a woman give birth
  • To save someone from a problem or crisis
  • To keep a promise; do what you say you would
  • To present something to a group, as a speech
  • To take something to a person or place

can

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US / kæn /

UK / kən,kæn /

A1
  • noun
  • A metal container for storing food
  • other
  • Able to; have the skill to; have the time to
  • verb
  • To have permission to
  • To be possible to do
  • To preserve food by sealing it in a metal container

guy

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US / ɡaɪ /

UK / ɡaɪ /

A1
  • noun
  • Man; boy; any person

and

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US / ənd /

UK / ənd, ən,ænd /

A1
  • conjunction
  • Used to refer to two or more things
  • Plus; in addition; on top of that
  • Used to introduce an action that follows another

minus

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US / ˈmaɪnəs /

UK / ˈmaɪnəs /

A2
  • adjecitve
  • Being close to the bottom of a letter grade
  • noun
  • Negative quality; disadvantage
  • Sign that indicates subtraction
  • preposition
  • Being less than zero in number
  • Used when subtracting one number from another
  • verb
  • To take one number away from another; subtract

from

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US / frəm /

UK / frʌm, frɑm,frəm /

A1
  • preposition
  • Starting at a particular place, time or level

polarity

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US / pə'lærətɪ /

UK / poˈlærɪti,pə- /

B1
  • noun
  • Relation between two opposite attributes

come

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US / kʌm /

UK / kʌm /

A1
  • verb
  • To arrive at a place
  • (Of mail) to be delivered
  • To move toward someone; go with someone
  • To reach a certain point or state

something

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US / ˈsʌmθɪŋ /

UK / ˈsʌmθɪŋ /

A1
  • adverb
  • In some degree or measure
  • noun
  • a person or thing of some value or consequence
  • pronoun
  • Thing that is not yet known or named
  • Approximately

where

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US / hwɛə /

UK / hwɛr, wɛr /

A1
  • conjunction
  • At or in the place which
  • In whatever place
  • pronoun
  • Word you use to ask the location of something

call

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US / kɔ:l /

UK / kɔl /

A1
  • noun
  • A order or request for action
  • The sound an animal makes, often when in danger
  • A correct prediction, e.g. a decision in a game
  • A short visit to a place or person
  • A decision by a referee or umpire in a game
  • verb
  • To make a request or order for action
  • (Animal) to make sounds to warn of danger
  • To announce the date of an election
  • To make a judgment about something
  • To give someone or something a name
  • To guess in advance the result or outcome
  • To visit a place or person for a short time
  • To phone someone
  • To speak, announce or shout in a loud voice

two

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US / tu: /

UK / tu /

A1
  • number
  • 2

put

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US / pʊt /

UK / pʊt /

A1
  • phrasal verb
  • to make a light stop shining by pressing or moving a switch
  • verb
  • To move or place a thing in a particular position
  • To rate something in importance or value
  • To write or say something in a certain manner

rest

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US / rest /

UK / rɛst /

A1
  • noun
  • Time when one relaxes, sleeps, or is inactive
  • State in which there is a lack of motion
  • Part of something remaining after some was used
  • verb
  • To stop working or avoid activity to recover
  • (Of dead person) to lie in a grave
  • To lean, support or place something against
  • To not be tired because you had enough sleep
  • Subtitles section
  • There's two kinds of ideal sources we're gonna talk about.
  • One is an ideal voltage source, and the other is an ideal current source.
  • A ideal voltage source, the symbol is, looks like a circle, like that.
  • We put a voltage indication right inside there.
  • That's called V, and this is a constant voltage.
  • What I've shown here is a constant voltage.
  • And that can come from a power supply, or it can come from a battery.
  • When it comes from a battery, we have a special symbol for that.
  • The battery symbol looks like this.
  • And the convention for this, we also label it V. The convention for the polarity of a battery symbol is the long line there is the plus terminal, and the short line right there, that guy is the minus terminal.
  • So that's the convention for a battery.
  • The other type of ideal source is called a current source.
  • And it also has a symbol like, with a circle.
  • And this one we put an arrow, and it goes in the direction of the current.
  • The current symbol is I. It can look like that, or we could point the arrow the other way, like that, depending on how the application goes.
  • And that's an ideal current source.
  • And those are the two symbols for constant Current.
  • Now, one of the things we can do is we can plot these, we can plot these two voltage sources, the voltage source and the current source.
  • We can plot them on a curve that has coordinates voltage and current.
  • So this would be called an IV curve, or an IV plot that we're about to do here.
  • For a constant voltage source, the voltage doesn't change.
  • The current goes up and down, depending on what the rest of the circuit demands.
  • But the current, the voltage, is the same everywhere.
  • So it plots something like this.
  • That would be the plot, the IV plot, of a constant voltage, where V equals some constant V.
  • And if we want to plot our constant current source on this kind of IV plot, this would be something where the current is always the same.
  • The current is the same, independent of the voltage.
  • And so a plot of that, for a positive current, would look like this.
  • And we would say something like I equals a constant I.
  • So that's the IV plot of a current source, and the IV plot of a voltage source.
  • All right, these are the two basic ways we deliver power or signals into circuits.
  • Now we have a complete set of elements that we can build things with.