Unit 2- Waves and Electricity Flashcards
This covers Unit 2 content
What is a transverse wave?
A transverse wave is a wave where the particles oscillate perpendicular to the direction of wave propagation.
What is a longitudinal wave?
A longitudinal wave is a wave where the particles oscillate parallel to the direction of wave propagation.
What is the difference between transverse and longitudinal waves?
In transverse waves, particle oscillation is perpendicular to wave propagation. While in longitudinal waves, particle oscillation is parallel to wave propagation.
Define wavelength.
Wavelength (λ) is the distance between two consecutive points in phase on a wave.
Define frequency.
Frequency (f) refers to the number of wave cycles per second.
Define Wave Speed.
Wave speed (v) is the speed at which a wave propagates. This is given by v=fλ
What is the principle of superposition?
When two waves overlap, the resultant displacement is the vector sum of the individual displacements.
State the relationship between intensity and amplitude of a wave?
Intensity is proportional to the square of the amplitude (I∝A^2)
What is diffraction?
Diffraction is the bending of waves around obstacles or through gaps.
When does diffraction occur most significantly?
It occurs most significantly when the gap size is comparable to the wavelength.
What is meant by constructive interference?
Constructive interference is when waves meet in phase, their amplitudes add up.
What is meant by destructive interference?
Destructive interference is when waves meet out of phase, their amplitudes cancel out.
Explain the formation of stationery/standing waves.
Stationery waves form when two waves of the same frequency and amplitude traveling in opposite directions interfere, creating nodes and anti-nodes.
What is the Doppler effect?
This is the change in frequency or wavelength of a wave as the source or the observer move relative to each other.
Define electric current.
Electric current (I) is the rate of flow of charge
Provide the formula for electric current.
I=Q/t, where Q is charge and t is time.
What is conventional current?
Conventional current is the flow of positive charge from the positive terminal to the negative terminal of a power source.
What is electron flow?
Electron flow is the actual movement of electrons, which occurs from the negative terminal to the positive terminal of a power source.
What is the difference between conventional current and electron flow?
Conventional current flows from positive to negative, while electron flow is the actual movement of electrons, which is from negative to positive.
What is Ohm’s Law?
Ohm’s Law states that the current through a conductor is directly proportional to the voltage across it, provided the temperature remains constant. (V=IR)
How is the resistivity of a material calculated?
ρ=RA/L, where R is resistance, A is cross-sectional area and L is length of the conductor.
State the formulas for total resistance in series circuits.
R total= R1+R2+R3+….
State the formulas for total resistance in parallel circuits
1/R total= 1/R1 + 1/R2 + 1/R3+…
Define Kirchhoff’s First Law.
The total current entering a junction equals the total current leaving it.
Define Kirchhoff’s Second Law.
The total electromotive force (EMF) around a closed loop equals the sum of potential drops.
How is power in an electrical circuit calculated?
P=VI, P=I^2, or P=v^2/R, depending on the known quantities.
Define potential difference.
The work done to move a unit charge between two points in a circuit.
Define Electromotive Force
Electromotive force is the energy supplied per unit charge by a source.
How is the internal resistance of a cell determined experimentally?
By plotting a graph of terminal potential difference (V) against current (I) and finding the gradient and intercept (V=EMF-Ir)
