1KM03 Basics of Electricity and Electronics Flashcards
What is electromotive force (EMF)?
The energy per unit charge that drives current around a circuit; measured in volts.
What is the unit of EMF?
Volt
What is the formula for EMF?
EMF = Work done / Charge (ℰ = W/Q)
Name three sources of EMF.
Battery
Generator
Solar cell
What is electric potential difference?
The work done to move a charge between two points
Measured in volts.
How does a battery create potential difference?
By separating charges through chemical reactions at the electrodes.
State Ohm’s Law.
V = I × R
What is resistance?
Opposition to current flow; measured in ohms (Ω).
What is conductance?
The inverse of resistance; measured in Siemens (S).
Give the formula for conductance.
G = 1 / R
What is the unit of electric charge?
Coulomb
What is the formula for current?
I = Q / t
What is the unit of current?
Ampere (A)
What is the formula for power in terms of voltage and current?
P = V × I
What is the formula for power in terms of current and resistance?
P = I² × R
What is the formula for power in terms of voltage and resistance?
P = V² / R
What is the unit & formula for electrical energy?
W = P × t
What is the unit of energy?
Joule (J)
Name one good conductor.
Copper
Name one good insulator.
Rubber
What is a semiconductor?
A material that behaves as a conductor under certain conditions.
Give two examples of semiconductors.
Silicon
Germanium
What is the difference between voltage and EMF?
EMF is the source of voltage; voltage is the potential difference between two points.
What is the relationship between power, voltage, and current?
Power = Voltage × Current (P = V × I)
