Phase II Block 5 Electromagnetic Radiation Flashcards
Light
Charge under acceleration producing EM radiation
- Vibrations in electric and magnetic fields, carrying energy and propagating at the speed of light.
Charged Particles
Experience electrostatic force in the presence of other matter.
Opposites attract
Likes repel
Coulomb’s Law
Mathematical definition of attractiveness and repulsiveness. Relationship between the charges and the distance between them.
Gauss’ Law for electricity
Charges are monopoles; net charge equals sum of positives and negatives
Drawing Field Lines
Rule 1 - high to low potential, positive to negative, north to south
Rule 2 - enter and leave radially/perpendicular
Rule 3 - number of field lines is proportional to the charge
Rule 4 - Never intersect
Rule 5 - density is proportional to the field strength
Electric Field
Charged particles accelerate to get EM radiation. Gradient from positive to negative
Faraday’s Law
Moving magnets create an electric field
Magnetic Field
Gradient from North to south.
Ampere’s Law
A moving current creates a magnetic field. Right hand rule - thumb up (current direction), fingers in (magnetic field direction)
Gauss’ Law For Magnetism
Magnets are dipole. Exits north to reenter south.
EM Waves
- Electric field is parallel to current, magnetic field is perpendicular to the current
- Propagate at the speed of light
- Charge under acceleration will produce radiation
- Simplified in Sine wave
- 2 sine waves are perpendicular to each other
- Both fields fully surround the source
Amplitude
Height. Maximum electric and magnetic field strength
Period
Time to travel one wavelength
Wavelength
Distance from peak to peak
Frequency
Wavelength per second
