Chapter 16 : Electric Circuits Flashcards
define current electricity
the flow of electrons through a conductor
define electromotive force
EMF
is the total energy supplied per coulomb per charge by the cell
define potential difference
the work done per unit charge
define current
the rate of flow of charge
define resistance
material’s opposition tot he flow of electric current
explain what conventional current is
charge flows from the positive pole of the cell through the circuit to the negative pole
higher potential to lower potential
describe what electron flow refers to
electrons flow through the circuit from the negative pole of the cell to the positive pole
define what ohm’s law refers to
current through a conductor is directly proportional to the potential difference across the conductor at a constant temp
explain briefly why cells in series last a shorter time than cells in parallel (4)
cells in series:
• cells go flat quicker
• current will be stronger because EMF gained is higher
cells in parallel:
• cells go flat slower
• current is weaker because EMF gained is lower
what is the formula for calculating 1 coulomb of charge?
1C = 1A x 1s
what is necessary for current to flow in a circuit? (2)
- closed circuit
* source of electrical potential energy ( battery/ cell )
what is the formula for potential difference?
V = W/Q
what’s the formula for resistance?
R = V/I
is V stays constant then higher the resistance then lower the current
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why do batteries go flat?
• chemical potential energy in the cell has been transferred and there’s no more reactants for ether chemical reaction
