CHAPTER 5 AND 6: FINALS REVIEW Flashcards
What is electricity?
all phenomena caused by positive and negative charges
What is electrical charge?
A property belonging to protons and electrons.
Protons posses a +ve charge while electrons carry a -ve charge
What is the difference between positively charged bodies and negatively charged bodies?
Positively charged bodies contain more protons than electrons
Negatively charged bodies contain more electrons than protons
What is an elementary charge? What is its value?
Charge carried out by one proton or electron (1.602x10thpwr-19)
What are the behaviours of electrically chraged matter? (9)
- Like charges repel, opposites attract
- Electric force causes either attraction or repulsion
- A charged object has an imbalance of charges
- Metals are good conductors due to the weak attraction between their nuclei and valence electrons, whihc allows said electrons to move between atoms
- Electrolytic solutions conduct electricity due to the movement of ions
- Insulation does not allow electron movement
- Non metals restrict the circulation and flow of their valence electrons
- Metalloids have varying levels of conductivity
- Electric charges affect objects at a distance by producing electrical fields
What is an electrical field?
Area of space where charged bodies can act on eachother
What is static electricity?
All phenomena related to electrical charges at rest
What is charging?
Creating an imbalance of charges in the elctrical charge of an object
How can you charge an object?
Friction: Rubbing two neutral bodies together, causing a transfer of electrons, therefore causing an imbalance.
Conduction: Putting an object in contact with a charged one, causing two similarly charged bodies but with weaker intensity
Induction: Charging without direct contact, causing a difference in polarity
How can electrical force be calculated?
Fe= (k)(q1)(q2)/r(thpwr2) k= coulomb's constant (9x10thpwr9 Nm(thpwr2)/C(thpwr2))
What is dynamic electricity?
all phenomena related to electrical charges in motion
What is electric current?
The ordely flow of negative charges carried by electrons
What is conventional current direction?
where positive particles go from the positive terminal to the negative terminal
What is current intensity?
Number of charges that flow past a given point in an electrical circuit every second
How do you calculate current intensity?
A= C/Δt
A: current intensity in A
C= charge in c
Δt= time in s
What is used to measure current intensity?
ammeter
What is potential difference?
Amount of energy tranferred between two point of an electrical circuit
How do you calculate potential difference?
V= E/q
V: potential difference in v
E: energy transferred in J
q: charge in C
what is used to measure potential difference?
Voltmeter
whats the difference between the installation of a voltmeter and an ammeter?
ammeter: installed in series
voltmeter: installed in parallel
What is resistance?
An object’s ability to restrict or hinder electrical flow
What can affect resistance?
Nature of the substance: poor conductors are better resistors
Length: the longer a wire the more resistance
Diameter: smaller diameter causes more resistance
Temperature: the warmer something is the better the resistance
How do you calculate resistance?
Ω= V/A
What is Ohm’s law?
the potential difference and current intensity are directly proprtional to the resistance
what does V=RI relate to?
Ohm”s law
What is electrical power?
How much work an electrical device can perform oer second
How do you calculate electrical power?
Pe=W/Δt
pe: electical power in W
W: work in J
Δt: time in seconds
What is the relationship betweem power and electrical energy?
wxs = 1J
what is one kWh equal to?
1000Wx 3600s = 3600000J
How do you calculate electrical energy?
E= PeΔt E= electrical energy in J or kWh Pe= electical power in W or kW Δt= in seconds or hours
What is an electrical circuit?What do they include? What is the difference between a series and parallel circuit?
An electrical circuit is a network where electrical charges flow in a loop. The include a power supply, elements that use the electrical energy (resistors), and wires that carry the charges
Series circuits are connected from end to end, only follows one path. Meaning that is one component is defective, the entire circuit will stop working. It= I1= I2= I3… and Vt= V1+V2+V3…
vs
Parallel circuits contain at least one branch emaning they can follow MORE THAN ONE path. Meaning that is one component is defective, elements in other branches will continue to function. It= I1+I2+I3… and Vt= V1=V2=V3…
What are the two principles of Kirchoff’s law?
- Current intensity into an element or a node of an electrical circuit = the intensity that flows out of said element or node
- The total energy aquired by the charges of the power supply = the total energy transferred by said charges no matter the pathway
What is Coulomb’s law?
the magnitude of the force between two immobile elctrically charged particles is proportional to the product of their charges and inversley proportional to the square distance between them
What is the difference between Req in series and in parallel?
Series: Req= R1+R2+R3…
Parallel: 1/(1/r1)+(1/r2)+(1/r3)
What is a magnet?
objects that attracts Fe, Ni or Co
What is magnetism?
all phenomena caused by magnets
What are domains?
Set of regions that when not alligned, does not make an object magnetized. When aligned however, the object is magnetized
What happensz if you were to place two north facing poles in front of eachother?
repulsion
What is a magnetic field?
Area of space where a magnet can act on another magnet
What is a ferromagnetic substance?
substance with the ability to acquire magnetic properties