Current, Voltage and Resistance Flashcards
What are the six common sources of EMF?
- Magnetic
- Chemical
- Friction
- Heat
- Pressure
- Light
When connecting a DC voltmeter across a load in a circuit indicated by a double subscript, where will you connect your positive (red) lead?
The first letter of the double subscript.
A burnt out lamp acts like “___” in a circuit?
An open circuit.
What are the two requirements to establish an electric current?
- An electric field or Potential difference
- A path.
What are three necessary elements of a functioning electrical circuit?
- An EMF source
- A path
- A resistive load
Ohm’s Law states…?
The current in a circuit is directly proportional to it’s EMF and inversely proportional to it’s resistance.
Quantity of charge is measured in “___”, we use the symbol “__” to denote it.
Coulombs (C)
Q = quantity of charge.
How do we define current mathematically?
I = Q/t (where t = time, Q = quantity of charge)
Approximately how many electrons are in a coulomb?
6.24 x 1018 electrons
What is conventional current flow sometimes referred to as?
Hole flow.
How would one create an electric field?
Separate two unlike charges.
What is the force that maintains an electrical potential difference, to prevent the voltage dissipating through the circuit?
Electromotive force.
What is resistance?
The opposition of a material to current flow.
Could voltage be described as an imbalance of electron distribution?
Yes.
How does current flow, conventionally?
From positive to negative.
