Physics Chapter 18 Flashcards
What does something have to do in order to be a source of emf?
It has to transform nonelectrical eneergy to electrical emergy.
What are examples of sources of emf?
Batteries and generators
Batteries turn chemical energy into electrical energy
Generators turn kinetic energy into electrical energy
What is emf?
It’s the source of potential difference (Voltage) and electrical energy
What can be determined about the emf and potential difference if resistance isn’t taken into consideration?
The voltage and emf are equal in that case.(across the source’s 2 terminals)
What;s the terminal voltage?
It’s the voltage across the battery’s 2 terminals
What’s a conventional current?
It’s a circuit in which the current flows from the positive to the negatice sides of the battery.
The potential difference across a load equals…
the terminal voltage
What can be determined about the emf and terminal voltage in a conventional current?
the terminal voltage is less than the emf
What;s a schematic diagram?
It’s an illustration that depicts the construction og electrical aparatus
What are the types of energy that a light bulb changed electrical energy to?
What does a basic electrical circuit contain?
A light bulb, a switch, and a wire.
What is another name for schematic diagram?
A circuit diagram.
What’s an electrical circuit?
A set of electrical components connected tsuch that they provide one or more complete paths for the the movement of charges (current).
What;s a load?
Any element or group of elements that dissisipates energy.
Why don’t we consider the wire or switch as a part of the load?
Because the energy that they dissisipate is negligible
What’s a short cirxuit?
It’s a situation where a circuit contains little resistance to the movement of charges..
What’s an example of a short circuit?
A wire that has low resistance is connected from one terminal of a battery to the other.
What is emf composed of? And what does it stad for?
It’s the source of potential difference and electrical energy in a cricuit.It stands for electromotive force.
What does voltage correspond to?
It corresponds to the work needed per unit of charge to move a test charge between the two points.
What must a device provide in order to be a source of emf?
It must increase the overall potential energy of charges circulating in a circuit.
The emf is…
the energy supplied per unit of charge supplied by a source of electric current
How can you think of emf as? And what are some examples?
You can think of it as a charge pump that forces the electrons to move towards a certain direction. Some examples are batteries and geerators.
In conventional currents…
the terminal coltage is less than the emf. The reason behind this is becasue the electrons are colliding within the battery while the charges are traveling from one terminal to the other.
The potential difference across a load equals…
the terminal voltage
How do you calculate the potential difference across a circuit with a light bulb and a battery?
V = IR
What types of circuits carry the same current through it’s resistors?
Series
What’s the equivalence resisstance?
The total resistance across a circuit.
How do you find the equivalence resistance in a series circuit?
The sum of all of the circuit;s resistances .
How do you find a circuits total voltage?
V = V1 + V2
or
V = I(R1+ R2)
or
V = ITr()
