Unit B | Forces and Fields Flashcards
What is a Field?
A region in which one particle interacts with another, “action at a distance”
What are Electric Fields?
A region in space where a
charged particle experiences an electric force
True or False?
Electric fields decrease in strength with
increasing distance from a charged particle
True!
What is a Point Charge?
A charge
that causes or
generates an electric
field
What is a Test Charge?
Small
charge placed in an
existing electric field
that experiences the
field
How are Electric Fields different then Gravitational Fields in terms of direction?
Unlike gravitation fields, which are always directed toward a
point mass (unidirectional), electric fields may be toward or
away from a point charge (bidirectional
When drawing Field lines for a positive Point Charge, what direction would the lines point to? (Inwards/Outwards)
Inwards (toward the point charge)!
When drawing Field lines for a negative Point Charge, what direction would the lines point to? (Inwards/Outwards)
Outwards (away from the point charge)!
Whats the relationship between the Magnitude of the Charge (q) and the Field Strength (Fe)?
How do they affect each other?
The larger the Charge, the greater the Electric Field Strength around
the Charge
True or False?
Point charges produce uniform electric fields
False!
Point charges produce non-uniform Electric Fields as the Field Strength varies due to position
What do Field Line indicate?
Both the direction of the field as well as the relative strength.
(The closer the lines are together, the greater the field strength)
When two or more
charges are creating an electric
field what is the result?
The result is the
vector sum of the
fields from all of the
charges
Why do excess charges distribute evenly on the surface of the sphere?
Electrons move as far apart as possible because of electrostatic
forces of repulsion
Why is the electrostatic field and force anywhere inside a charged conductor is zero?
Because there are no excess free charges inside the conductor. This is due to forces of repulsion causing the charges distribute evenly on the surface
What is Electric Potential Energy (Ep or ΔEp)?
The energy stored in a charged particle due to its position in an electric field
(or the work needed to move a charge against an electric field)
If q+ is moved toward a positive point charge, work is done against the electric field, so
Ep of the charge ____________ .(Increase/Decrease)
Increase!
q+ will gain more potential to go away as it feels repulsion (like charges repel)
If q+ is moved toward a negative point charge, work is done by the electric field,
therefore Ep ____________. (Increase/Decrease)
Decrease!
The field is doing the work (opposites attract), in turn p+ loses potential because there is no need to do work
