4.1 Charge And Current Flashcards
What is a conductor?
A material that allows the flow of electrical charge. Good conductors have a larger amount of free charge carriers to carry a current.
What is conservation of charge?
The total charge in a system cannot be changed.
What is conventional current?
The flow from positive to negative, used to describe the direction of current in a circuit.
What is the coulumb?
The unit of charge.
What is electric current?
The rate of flow of charge.
What are electrolytes?
Substances that contain ions when dissolved in a solution act as charge carriers and allow current to flow.
What is electron flow?
The opposite direction to conventional current flow. Electrons flow from negative to positive.
What is elementary charge?
The smallest possible charge, equal to the charge of an electron.
1.602 × 10 ^ -19
What are insulators?
A material that has no free charge carriers and so doesn’t allow the flow of electrical charge.
What is Kirchhoffs First Law?
A consequence of the conservation of charge. The total current entering a junction must equal the total current, leaving it.
What is mean Drift Velocity?
The average velocity of an electron passing through an object. It is proportional to the current and inversely proportional to the number of charge carriers and the cross-sectional area of the object.
What is the quantisation of Charge?
The idea that charge can only exist in discrete packets of multiples of the elementary charge.
What are semiconductors?
A matieral that has the ability to change its number of charge carriers, and so its ability to conduct electricity.
Light dependent resistors and thermistors are examples.
What is the equation for charge?
Charge = current x time
Q = IT
What is the equation for mean Drift Velocity?
Current = cross sectional area x number density of charge carriers x charge of single charge carrier ( typically electron ) x mean Drift Velocity
I = Anev
