Module 4 - Chapter 8 - Charge and Current Flashcards
What is the unit for electric current?
Amperes (A)
What is electric current?
Electric current is defined as the flow rate of charge.
State the equation to find electric current
I = Q/t
current = charge / time
What happens when a positively charged object interacts with a negatively charged object?
They will attract towards each other, if their charges were similar, they would repel each other.
What is the unit for electric charge?
Coulombs (C)
What is one 1 coulomb in base units?
From Q = It, 1 coulomb is 1 ampere second (As)
What is the elementary charge?
1.6 x 10⁻¹⁹
How do you find the net charge of an object?
Q = ∓ne
charge = (+ or -) number of electrons x elementary charge
What is the difference between conventional current and electron flow?
Electron flow is negative to positive in a circuit and conventional current is positive to negative in a circuit.
What is used to measure the electric current?
An ammeter is used to measure electric current.
Are ammeters placed in series or parallel?
Ammeters are placed in series.
What is Kirchoff’s first law?
For any point in an electrical circuit, the sum of currents into that point is equal to the sum of currents out of that point.
What is number density?
Number density is the number of free charge carriers per unit volume.
What is mean drift velocity?
Mean drift velocity is the average velocity attained by charged particles through a material due to an electric field.
What is the equation for mean drift velocity?
I = Anev
current (A) = cross-sectional area (m²) x number density x elementary charge x mean drift velocity (m/s)
