Year 11 Term 2 Flashcards
Distinguish between temperature and heat
Temperature is the average kinetic energy of the particles within a system
Heat is the thermal energy transferred between 2 systems due to a temperature difference
Define temperature
Temperature is the average kinetic energy of the particles within a system
Define heat
Heat is the thermal energy transferred between 2 systems due to a temperature difference
Convert Kelvin to Celsius
T(K) = θ(°C) + 273
Define internal energy
Internal Energy is the total amount of kinetic and potential energy contained within a particle; basically the equivalent of mechanical energy
Heat Energy Formula:
Q = mcΔT
where:
Q = energy (J)
m = mass (kg)
c = specific heat capacity
T = temperature (K)
Explain why the latent heat of fusion and vapourisation exists
The latent heat of fusion and vapourisation is when heat is transfer to the system but the temperature does not rise. This is as the heat energy is needed to change the state of matter
Define Latent Heat of Fusion
Latent Heat of Fusion describes the energy required to change state of matter from solid to liquid
Define Latent Heat of Vapourisation
Latent Heat of Vaporisation describes the energy required to change state of matter from liquid to gas
Latent Heat Formula:
Q = mL
where:
Q = energy (J)
m = mass (kg)
L = specific latent heat
Explain why the radiation from a blackbody is indicative of the internal temperature
A blackbody absorbs all radiation, meaning all radiation is from within
Explain the purpose of double brick houses and double glazing
It uses the low heat conductivity of air to trap warmth, which is unable to conduct
Define blackbody
Blackbodies are a special type of radiation with reference to a theoretical radiator that perfectly absorbs all radiation and re-radiates it
Define conduction
Conduction is the transfer of heat by physical contact
The areas of higher temperature will be transferred to the areas of lower temperature due to the collisions of particles
Identify the methods of heat transfer
Methods of Heat Transfer
- Conduction
- Convection
- Radiation
Define blackbody radiation curve
Blackbody Radiation Curve is one that depicts all the different wavelengths of radiation
True or False. Radiation requires a medium
False. As radiation involves the emission of electromagnetic waves, a medium is not required, opposed to conduction and convection
Explain what convection currents are
Convection currents are currents formed by the expanding of hot fluids, becoming less dense and rising, forming a loop
Identify the factors on the itensity of radiation
A (radiating area) and T^4 (Temperature)
Define radiation
Radiation is the transfer of heat through the emission of electromagnetic waves, which carry energy
Rate of energy transfer (conduction):
Q/t = (kAΔT)/d
where:
Q = energy (J)
t = time (s)
k = thermal conductivity
A = cross sectional area (ms^2)
T = temperature (K)
d = distance (m)
Define convection
Convection is the transfer of heat through the motion of a fluid, such a water or air, where the heated fluid flows away from the source, carrying energy
Identify the importance of the peak of the blackbody radiation curve
The peak is the colour of the blackbody
The Coulomb is the SI unit of?
Coulomb is the SI unit of electric charge
Value of a Coulomb
1 C = 6.25 × 10^18 electrons or protons
Define neutral bodies
Neutral Bodies are objects with the same amount of electrons and protons
Define charged bodies
Charged Bodies are objects with unequal amount of electrons and protons, where positively charged bodies have a deficiency of electrons and negatively charged bodies have excess electrons
Define electroscope
Electroscope is an instrument that detects whether an object is a charged body, but cannot indicate the sign
Process of identifying charge
Using an electroscope.
The basic process is: you bring an object near the top of the instrument if the object is charged, the particles of the same sign are repel to the gold leaves which repel between each other
Define conductor
Conductor is a material that contains free moving charge carriers
Define insulator
Insulator is a material that does not contain free moving charge carriers
Identify the methods of charging
Methods of Charging:
- Triboelectric (Friction)
- Conduction
- Induction
Define triboelectric
Triboelectric is the process of charging where two bodies made of different materials are rubbed together, transferring electrons
Recall how one identifies which direction the electrons travel in triboelectric
The electrons travel to the material with higher electron affinity
Define conduction (charging)
Conduction is when a charged conductor is brought into contract with an uncharged conductor, sharing the total charge
Define induction
Induction is the process of charging through the presence of a charged particle, using electrostatic attraction and repulsion forces
Describe Coulomb’s Law
Coulomb’s Law describes the force of attraction and repulsion between 2 point-charges
Identify the features of electric field lines
Features:
- Electric Fields are vectors that travel from positive to negative
- Electric field lines never cross
- The density of electric field lines dictates the magnitude of the electric field
- The tangential direction on field lines represent the direction of force on positive charges at that specific point
- Positive charges experience a force along field lines
- Negative charges experience a force against field lines
Electric field and force formula
F=qE
Define electric potential energy
Electric Potential Energy is the work exerted from an electric field on a charged particle
Electric potential energy and work formula
W=-ΔU
Define voltage
Voltage, or electric potential, is the change in potential energy per unit charge between 2 points
Identify what electric potential is
Electric potential is voltage
Positive charges move from _ to _ electric potential
Positive charges move from high to low electric potential
Negative charges move from _ to _ electrical potential
Negative charges move from low to high electrical potential
Voltage formula
V=ΔU/q=-W/q
Describe how one can form an uniform electric field
An uniform electric field can be formed using 2 horizontal parallel electric field plates, where one is positive and the other is negative
Define equipotential lines
Equipotential Lines are lines that are intersect the electric field lines at right angles (perpendicular)
Relationship of equipotential lines and work
Moving a charge along an equipotential line does no work
Work done between 2 equipotential lines is independent of the path taken
Define current
Electric Current (I) is the rate at which charge (q) flows past a given cross-sectional area with respect to time (t)
I=q/t
Define battery
Battery is the energy source where chemical energy is converted into electrical energy (voltage difference between terminals) which pushes electrons out of the (-) terminal and towards the (+) terminal.
Define real current
Real Current is the flow of electrons undergoes resistance which produces energy
Define conventional current
Conventional Current describes the hypothetical direction of positive charge flow which is opposite to the real current
Ohm’s Law:
V=IR
Define voltmeter
Voltmeter is an instrument that measures voltage drop or electric potential difference between 2 points in a circuit; connected in parallel with the section of the circuit
Ideally, a voltmeter should have infinite resistance so no current passes through it
Define anmeter
Ammeter is an instrument that measures the current flowing through a specific point within the circuit; connected in series within the circuit
Ideally, an ammeter should have zero resistance, so it does not change the overall resistance of the circuit and thereby the current it measures
Explain why most resistors are non-ohmic
Most resistors are non-ohmic as the collisions between electrons and the metallic lattice as heat is produced (collision theory)
Define ohmic resistors
Resistors that follow Ohm’s Law
Define non-ohmic reisistors
Resistors that do not follow Ohm’s Law
Define resistance
The resistance of a conductor is a result of collisions between the free electrons and the lattice of positive ions; more the collisions, the higher the resistance
Factors impacting resistance
Factors impacting resistance:
- Length
- Material
- Area of Cross-section
- Temperature
Resistance formula
R = (plT)/A
Define power
Power is a resistor’s ability to do work, indicated through the energy produced (heat, light, sound, kinetic energy etc)
Power formula
P=W/t=(Vq)/t=VI=I^2*R=V^2/R
In series circuits…
In Series Circuits:
- The current is constant
- Total voltage equals to the sum of the individual voltage drop
- Total resistance equals to the sum of the individual resistances
In parallel circuits…
In Parallel Circuits:
- Total current equals to the sum of the individual currents
- The voltage is constant
- The inverse of total resistance equals to the sum of the inverse of the individual resistances
State Kirchhoff’s First Law
Kirchhoff’s First Law (Junction Law) states that the total current entering a junction is equal to the total current leaving the junction
State Kirchhoff’s Second Law
Kirchhoff’s Second Law (Loop Law) states the algebraic sum of the changes in potential encountered in a complete traversal of a closed circuit loop must be zero
The magnetic north pole of a magnet is the geographic _ pole
The magnetic north pole of a magnet is the geographic south pole
The magnetic south pole of a magnet is the geographic _ pole
The magnetic south pole of a magnet is the geographic north pole
True or False. Magnetic monopoles cannot exist
True
Define induced mangetism
Induced magnetism is a phenomenon when a magnet is brought close to a magnetic material, the object can be temporarily magnetised, extending the magnet
Features of Magnetic Field Lines
Magnetic Field Lines
- Indicate the direction a magnet’s North pole would point
- Vector Quantity
- Field lines never cross
- Externally, field lines flow from the North pole to the South pole
- Internally, field lines flow from the South pole to the North pole
- Denser Field Lines indicate more strength
- Always form self-closed loops
True or False. A moving charge produces its own magnetic field
True
Purpose of Right Hand Rule
Right Hand Rule indicates the current flow and direction of the magnetic field for a positive charge
Magnetic fields - X
X is into the page
Magnetic fields - ⋅
⋅ is out of the page
Define solenoid
Solenoid is an electromagnet composed of coils of wire
Recall the denominator for magnetic field from a current carrying wire
2πr
Recall the denominator for magnetic field from a current carrying loop
2r
Recall the denominator for magnetic field from a solenoid
L
Purpose of RIght Hand Palm Rule
Right Hand Palm Rule indicates the current flow, direction of the magnetic field for a positive charge, and the resultant force
µ unit
10^-6
n unit
10^-9
m unit
10^-3
