Module 7 Flashcards
It is the motion of charge from one region to another.
Current
In electrostatics, electric field everywhere within a conductor is _______.
zero; no current
In general, free electrons move __________ in a conductor.
randomly
It is the rate of flow of electrons in a circuit.
Electric Current
It is the unit of current.
Ampere
The unit of current (A) is named after:
Andre’ Marie Ampere
It is expressed in terms of the number of coulombs per second going past a given point on a wire.
Ampere
It is the result of acceleration of electrons due to the electric field and collisions with atoms.
Vd
The direction of I is in the same direction where there is a flow of positive charge.
Conventional Current
Current is not a _______.
vector
It is the amount of electric current flowing per unit cross-sectional area of a material.
Current Density
It is the average velocity of the free charges.
Drift Velocity
The direction of drift velocity is __________ to the electric field for electrons.
opposite
The electric field in the conductor causes the electrons to drift in the _________ to the field, since they are negative.
opposite direction
Vector current density is _________ in the direction of the field.
always
Current due to charges is the ____________ for each charge.
sum of all currents
Total current density is the sum of the ___________.
individual current densities.
It is the electrical resistance of a conductor of a unit cross-sectional area and unit length.
Resistivity
It is a characteristic property of each material.
Resistivity
Resistivity is useful in comparing various materials on the basis of their ability to ____________.
conduct electric currents
High resistivity designates _____ conductors.
poor
