ANSWERS 2026 EDITION
High Potential Magnesium
-1.75
Magnesium Alloy
-1.60
Zinc
-1.10
Aluminum Alloy
-1.05
Clean Carbon Steel
-0.50 to -0.80
Rusted Carbon Steel
-0.20 to -0.50
Cast/Ductile Iron
-0.50
Lead
-0.50
Steel in Concrete
-0.20
Copper
-0.20
High Silicon Iron
-0.20
Carbon, Graphite
+0.30
Electrons (-)
Negatively charged particles
Voltage (E or V)
, An electromotive force (emf) or potential difference expressed in volts. (The force that puts charges in
motion)
Volt (V)
Joule per coulomb, where joule is a unit of energy and a coulomb is a unit of charge
Current (I)
The rate of flow of charge is measured in amperes. (amps)
Ampere / Amps (A)
A unit of electric current equal to a flow of one coulomb per second.
Coulomb is a unit equal to
6.242 x 10^18 electron charges
Resistance (R)
Ohms (Ω)
Ohm's Law
E=IR or V=IR
Power
The energy used by an electrical device (measured in watts). P=EI
P=I^2R
Kirchoff's Law - Voltage
The sum of the source voltages around any circuit equals the sum of the voltage drops across the
resistances in the circuit. Source Voltages (E) [18V + 6V] = IR Drops (V) [12V + 8V + 4V]
ET= V1 + V2 + V3
Kirchoff's Law - Current
Current entering a junction equals the current leaving a junction. Current In (6 A) = Current Out (4 + 2) A
IT = I1 + I2
Series Circuits
The same current flows in a continuous path from the source voltage through the various loads and back
to the source.
The sum of the voltage drops must __________
add up to the source voltage (Kirchoff's voltage law)
Total resistance of a serious circuit __________
equals the sum of the individual resistances. RT = R1 + R2 + R3