Download Electric Fields and Potential

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Electric Fields and Potential
Force Fields
Forces act without _____________ between objects
____________________ field pull mass towards earth
_____________________ field surrounds electrically charged objects
Explains ____________________________
Electric Field
Proposed by _______________________ (1830’s)
Has both _______________ (strength) and ____________________
Magnitude measured by _______________ exerted on charged particle in
the field
Direction is that of the force on a small positive “__________________”
Can be visualized by ________________________ lines (lines of force)
Field lines start on _______________ charges, end on
__________________________
Arrows show __________________, away from positive, towards negative
Electric Shielding
Excess charge always located ______________________ of a conductor
Electric field inside conductor is __________________________
Effects of surface charge cancel so no effect ________________________________
If surface is sphere, charge will be ____________________________ on surface
If shape is irregular, charges _____________________________ at points & corners
Electrical components often housed inside metal boxes to ___________________ from external fields
Cables often have shielding to reduce stray signals from ___________________________________
Cars and airplanes safe from _____________________________
Electrical Potential Energy
__________________ must be done to move charged object into electrical field, like lifting weight in
gravitational field
Work done increases ________________________ of charged object
If object is released, potential energy will be converted to ______________________________
Electric Potential
If amount of charge is increased, amount of ______________ must increase to raise potential energy of
object.
More convenient term is ___________________, electric potential energy divided by amount of charge
present
At any point in field, _______________ is same, regardless how much charge is present
Unit of potential is _____________ (V)
1 volt = __________________________
Commonly called __________________
Voltage is _________________________ of amount of charge; high voltages possible with very little charge
present, therefore little energy
Capacitors
Capacitor is device used to _______________________
Consists of two _________________________ separated by an insulator
No __________________________ between plates
____________________ are pushed onto one plate by battery which pushes electrons off the other plate
This stores charge on the plates and energy in the _______________________ between the plates
Capacitor can be _____________________, releasing stored energy
Commercial capacitors made in many different forms, very common in ____________________