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REGENTS PHYSICS
ELECTRICITY
ELECTRIC FIELDS
ELECTRIC FIELD
Much like a Gravitational Field.
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A collection of “Lines of Force”.
Gravitational Field
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Electrical Field
Field lines always point from ____________ to _______________.
ELECTRICAL FIELD EQUATION
E=F
Reference Tables
q
where q is the charge on the object that is within the field.
Example: What is the magnitude of the electric field strength at a point in a field where an
electron experiences a 2.0 Newton force?
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EXAMPLES OF ELECTRIC FIELDS AROUND POINT CHARGES
-Draw the Electrical Fields for the following situations.
-Where would the Electric Field be the strongest in each case?
EXAMPLES OF ELECTRIC FIELDS AROUND PARALLEL PLATES
Parallel plates create a __________________ electrical field between them. The electrical force
is the same everywhere within the two plates.
- Work is done if a charged particle is forced to a plate that has the same sign as the plate.
- The charged particle has gained ELECTRICAL ______________ Energy.
-This would be converted into ____________ Energy if the charged particle were
released.
-Kinematic Equations could be used to determine the velocity and the acceleration
of the charged particle.
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POTENTIAL DIFFERENCE
The work done in moving a charged particle “against its will” between two plates can be used to
determine the _______________ DIFFERENCE between the two plates.
q
V=W
Reference Tables
where V is called the Potential Difference or the ________________.
and W is the work done in moving the charged object “against its will” between the plates.
and q is the charge on the particle that is in the field.
- Potential Difference is measured in VOLTS.
Example: Moving a point charge of 2.3 x 10-19 Coulombs between points A and B in an electric
field requires 4.2 x 10-18 joules of energy. What is the potential difference between these points?
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ELECTRON VOLT
The work done in moving single electrical charges can be very small.
Example: How much work is done in moving a 1.4 x 10-19 Coulomb electrical charge between
two parallel plates with a potential difference of 10 Volts?
This is a very small amount of work.
- We use a different unit, rather than the Joule, to describe this work for small charges.
- It is called the ____________ _________.
- In the above example, you divide the amount of work in Joules by the “Elemental
Charge”.
________________ Joules
1.6 x 10-19
= ________ ELECTRON VOLTS
Coulombs
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