Current, Voltage and Resistance

List six methods of producing an electromotive force.

1. Magnetic. Ex. generator. 2. Chemical. Ex. battery. 3. Friction. Ex. Van de Graaf generator. 4. Heat. Ex. thermocouple. 5. Light. Ex. solar cells. 6. Pressure. Ex. piezo crystal.

What is the number of electrons for one unit of charge?

6.28 * 10^18 electrons.

What is the unit of measurement for electric current and it's symbol?

Ampere, A.

Define electrical current.

An electric current is a flow of electrons from a negatively charged point to a positively charged point.

Describe conventional current flow.

Conventional current flow is from positive to negative and is opposite to electron flow.

What is the unit of measurement of charge and it's symbol?

Coulomb, C.

State the symbols used to represent source voltage.

E.

What is the name of the force that maintains a voltage?

Electromotive force.

State Ohm's law in the form of an equation.

I = E/R I = current, measured in amperes (A) E = emf, measured in volts (V) R = resistance, measured in ohms (Ω)

Write an equation to state the relationship between current, charge and time?

I = Q/t Q = quantity of charge in coulombs (C) I = current in amperes (A) t = time in seconds (s)

What is the symbol for electric current?

I.

State the unit of measurement for resistance and it's symbol.

Ohms,Ω.

Define one volt in terms of Ohm's law.

One volt is the value of the difference in charge will cause a current of one ampere to flow in a circuit with a resistance of one ohm.

What is the symbol for electrical charge?

Q.

Define resistance.

Resistance is the property of a material that opposes the flow of an electric current.

Describe static electricity.

Static electricity is the build-up of charge on a insulated object.

Define electric circuit.

The connection of the source of emf to both ends of a conductor.

How is Ohm's law stated?

The current is directly proportional to the emf and the current is inversely proportional to the resistance.

Define voltage drop.

The difference in charge measured across the load.

Define voltage rise.

The source or applied voltage (emf).

State the symbols used to represent voltage drop.

V with subscript.

State the unit of measurement for voltage and it's symbol.

Volt, V.

Define voltage.

Voltage is an imbalance of electron charges between two points.

State the abbreviation for this force.

emf.