Flashcards
Electric current
Cards in this deck (14)
- 1Which way does conventional current flowFrom positive to negative as this was the original theory but we now know that it flows from the negative electrode to the positive electrode
- 2What makes a metal such a good conductorThe free electrons inside it which can carry a current therefore making it ideal for conducting. This is because for conductive metals such as copper this outer elecron manages to break free therefore being able to a conductive electron. The metal does not change as there are an equal amount of positive ions to electrons therefore the charge of the metal is neutral.
- 3How does current flowCurrent flows from the negative node to the positive node which is the opposite to the convential flow of current. It flows as the negative electrodes are attracted to the positive node therefore carrying energy along the wire reaching the positve node.
- 4What flows in the same direction as the particlesI=Current
- 5What is a solution which conducts called and what does it containAn electrolyte and it contains both positve and negative ions.
- 6What is 1 unit of charge equal toCurrent x Time
- 7Define 1 coulomb (1 unit of charge)1 coulomb is the amount of charge which flows past a point in a circuit in a time of 1 sec when the current is 1 amp
- 8What is elementary charge and what is it equal toThis is the magnitude of the charge of an electron and is equal to 1.6 x 10^-19
- 9What is Kirchoff's First lawThe sum of the current going into a junction is equal to the sum of the current leaving it.
- 10Using Kirchoff's first law why does L1=L2+L3 when two curent are leaving the same pointThe current going into any point on a circuit is equal to the current leaving it.
- 11How can you test Kirchoff's first lawBy connecting ammeters at different points in the circuit where the current divides. Though this would only work in a series circuit as you must recall that the current is only equal throughout in a series circuit.
- 12What does n mean in an equation for current and what is the equationn is the number density and this is the amount of electrons per unt volume for example coppers 10^29.
The equation in which it is used for is I=NEAV - 13What does v stand for in the equation for currentv is equal to the mean drift velocity.
- 14Why is the flow of current slow in a circuitbecause there is vibrating metal ions in the way which mean the electrons regularly hit into them causing them to move about a lot so the overall distance is much greater than the overall displacement due to the drift velocity
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- Physics Flashcards on Electric current, created by jromay142 on 31/05/2014.
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