Electric Charges and Electric Force
What instrument is commonly used to measure electric current?
Ohmmeter
Voltmeter
Galvanometer
Ammeter
How does inserting a dielectric material between two charged plates affect capacitance compared with having just air or vacuum between them?
Capacitance remains unchanged since it depends primarily on plate area not intervening materials.
The capacitance decreases because dielectrics add resistance to charge flow across plates.
Capacitance oscillates depending on orientation thickness said dielectric.
The capacitance increases because dielectric materials reduce the electric field within themselves compared with air or vacuum.
What alteration can be made to an electrostatics demonstration involving suspended charged spheres that will maximize their repulsion without altering their charges or masses?
Reduce humidity in the air surrounding spheres significantly.
Increase ambient light level around spheres considerably.
Cool down temperatures around spheres well below room temperature.
Apply a strong magnetic field perpendicular to line joining centers of spheres.
Considering energy conservation laws, how does increasing one charged particle’s kinetic energy impact another stationary identical charged particle within an isolated system?
Potential energy remains constant while all added kinetic energy transfers as heat through radiation emitted by accelerated charges.
The stationary particle gains no kinetic energy since conservation laws ensure that total mechanical energy does not change within such systems.
It increases potential energy due to increased separation distance resulting from repulsion forces acting on both particles.
It decreases potential energy between them while increasing total kinetic energy until electrical repulsion stops further conversion.
Two point charges are separated by a certain distance in a vacuum; if the distance between them is halved, how does the electric force they exert on each other change?
It decreases by a factor of four.
It decreases by a factor of two.
It increases by a factor of four.
It increases by a factor of two.
What happens to the magnitude of the electric force between two charged objects when the distance between them is doubled?
It doubles.
It decreases by a factor of four (quadratic relationship).
It halves.
It remains unchanged.
What is the unit of electric charge?
Coulomb
Newton
Watt
Joule

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Why do objects charged electrostatically tend to lose charge to surrounding air moisture over time?
Air pressure increases around the charged object, forcing charge to disperse.
Moisture ionizes surrounding gas, creating an electric wind that blows charge away.
Moisture causes the temperature to rise until thermal degradation releases charge.
Electric charge is transferred to the naturally moist air particles, creating a conduction pathway.
What role does dielectric material play when inserted between plates of a capacitor that is connected across a constant voltage power supply?
It increases capacitance allowing more charge storage at same voltage due polarization aligning molecular dipoles reducing effective electric field.
Material presence enhances strength external applied electrical fields inside capacitor effectively amplifying circuit power output proportionally thickness utilized layer.
Dielectric insertion decreases overall charge capacity since insulators block flow reducing amount cumulatively preserved upon plates at given voltage.
The dielectric merely acts thermal buffer slowing temperature rise otherwise induced via Joule heating under continuous current conditions during charging.
Apart from increasing charge magnitude, what change in experimental configuration would most significantly increase electric force between two pendulum-bob-like charged objects suspended from insulating threads in a test of Coulomb's law?
Placing additional light source focused on dangling bobs to heat them up and potentially increase charge carrier activity has a minor impact on overall forces since the amount of charge is not changed and heating might cause dissipation instead.
Extending suspension length of threads making bobs hang lower does not significantly impact measured force related to charge interaction, only affected by distance changes in line joining centers of objects.
Changing the material of the threads to carbon fiber threads of lesser diameter and lower electrical conductivity increases force by maintaining charges better than insulating threads.
Replacing pendulum bobs with larger fully conductive spheres same size as charged objects decreases force due to bigger masses adding gravitational attraction to electrical repulsion.