Flashcards in electricity Deck (48):
What does every atom consist of ?
Proton & neutron in nuclei, electron distributed evenly
Protons are x many times more massive than electrons, do they carry the same amount of charge?
What is a normal atom like?
No net charge bc equal amount of electrons as there are protons in the nucleus
What is the conservation of charge?
electrons are simply transferred from one material to another. they aren't created or destroyed.
What is lightning?
electrical discharge between cloud and oppositely charged ground or or oppositely charged part of the cloud
What is the difference between gravitational and electrical forces?
1. Gravity always attracts, but electric force can either attract or repel
2. Electric forces are vastly stronger than gravitational
electrons are tightly bound and belong to particular atoms, poor conductors of heat
one or more of the electrons in the outer shell are not tightly anchored to the nuclei of a particular atom
a charged object will attract a neutral object.
A negatively charged rod will do what for the positive part of an atom and what for a negative part of an atom?
positive- tug toward rod
negative- push away from rod
What causes a stream of water to be deflected when you bring a charged object next to it?
polarization of water molecule
Electric fields are
electric force on positive unit charges
Rule for electric field lines
-direct from positive charge and toward negative charge
-number of electric field lines per unit is proportional to the strength of the electric force
-tangent of electric field line is the direction of electric force on positive charge
energy per charge. unit = joule/columb which we call a volt
The lamp would not grow when it is
held both ends equidistance from the
charged Van De Graff Generator. But
when one end is closer to the Dome
than other end, a current is established
and it glows. Why?
The end of the lamp that is held closer to Dome is at higher electric potential than the farther end
When you move positive charge, what happens?
positive charges are repelled, so you have to exert force in order to push closer
The work of a charge is
stored as electric potential energy of charge
If you release charge, it will
fly away and its potential energy will be converted into kinetic energy
devices that store charge and electric energy. They are two conductors separated by an insulator
Atom nuclei of almost all elements consist of
protons & neutrons
What force binds atoms together to form molecules?
Which force binds billions of stars to form galaxies?
What force confines protons inside a tiny nucleus?
What are the four forces in the universe?
Gravity, strong nuclear, weak nuclear, electromagnetic
Two protons attract each other gravitationally and repel each other electrically... the greater force is
Two charged particles are released. As they move, force between them decreases because they are....
like signs (distance increases)
Two charged particles are released. As they move, force between them increases because they are....
opposite signs (distance decreases)
Difference between conductors and insulators?
Freely moving electrons vs bound electrons
All conductors have a _ resistance which creates heat.
no resistance so they will generate no heat
What is current
I (Ampere) charge flow in a closed circuit
What is voltage?
V (Volt) electrical potential difference across its ends which drives charge
What is resistance?
R (Ohm): resists the flow of charge
I = V/R
What is the current through a 10-ohm resistor connected to a 120-v power supply?
When a 10-V battery is connected to a resistor. the current in the resistor is 2A. What is the resistors value?
What is electric potential? What causes charge to move
VOLT- drive charge to move... difference in electrical P.E.
Current will flow from x electric potential to x electric
high to low
The longer the conductor is
higher the resistance.
The smaller its area
the higher its resistance
current has a single path; break anywhere in path and the other bulbs go out (they are wired together one after another)
To get a large flow/current...
high pressure/voltage is required
- each bulb is directly connected to the battery w/ no other bulb intervening
-cars/houses are wired this way
the voltage across each of the components is the same, and the total current is the sum of the currents through each component
current that only flows in one direction (battery)
current flows back and forth with alternating direction. Frequency of 60 cycles per second. Current alternates direction 120 times per second (household appliance/power plant)