Electromagnetism Flashcards
What is an electric field?
A region that surrounds electrically charged particles in which a force is exerted on other electrically charged particles.
What is electric field strength?
Electric field strength at a given point is defined as the force per unit of positive charge at that point.
What does an electric field diagram look like when drawing around a positive point charge?
Straight lines perpendicular to the charge with arrows pointing away from the charge.
What does an electric field diagram look like when drawing around a negative point charge?
Straight lines perpendicular to the charge with arrows pointing towards the charge.
What does an electric field diagram look like when drawing around a positive and a negative point charge?
Lines will be perpendicular to the charges but will curve from the positive charge towards the negative charge with the arrows facing away from the positive and towards the negative.
What is electrical potential at a point?
The work done to bring a unit positive charge from Infinity to that point.
What is the case with the energy required to move charge between two points in an electric field?
energy required to move charge between two points in an electric field is independent of the path taken.
Describe milkman’s experimental method for determining the charge on an electron
Atomiser sprayed tiny oil droplets into chamber, pulled through a small hole by gravity and examined using a microscope . Observing terminal velocity allowed him to calculate the droplets mass.
Electric field applied allowed him to balance forces.
Stationary oil droplets , X-rays ionise the air varying charge on droplets.
What is an electron volt
The energy acquired when one electron accelerates through a potential difference of one volt.
How to convert between electron volts and joules
Multiply the number of electron volts by the charge on an electron.
Ferromagnetism dipoles
Iron , nickel and cobalt have dipoles that can be made to align resulting in the material becoming magnetised
Explain the helical path followed by a charged particle in a magnetic field
