ECE 331 EXAM 1 QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026
How fast do electrons travel in a good conductor? What is this velocity called? - Answers 0.1 mm/s
drift velocity
The prongs on a typical grounded plug are more properly called what? What about the receptacle? -
Answers Blades and ground pin; Receptacle: slots and ground hole
What's the voltage of a typical wall socket in the U.S.? - Answers 120 V
Do birds land on distribution lines? Do they land on any wires? Explain why or why not. - Answers
Birds land on all cables, and particularly like the heat of distribution lines in the winter.
What's the meaning of the ground node in the node voltage analysis of a circuit. - Answers It's the
reference node and has 0V potential relative to itself.
How much current flows in a typical lightning bolt? - Answers on the order of 10 kA - 40 kA
What's the voltage of a car battery? How is it set up? - Answers 12 V
6 cells are connected in series, with 2 volts per cell
What is in one cell? - Answers - Sulfuric Acid (H2SO4) + water (electrolyte)
- 2 plates
----> 1 plate made of sponge lead
----> 1 plate made of lead dioxide
What does the chemical reaction of sulfuric acid on lead produce... - Answers Lead sulfate and e- are
liberated
Voltmeters measure the voltage drop from... - Answers The red probe to the black probe
Does the red probe connect to the positive or negative terminal? - Answers Positive
Does the black probe connect to the positive or negative terminal? - Answers Negative
A complete description of voltage requires which two things? - Answers 1) A value (positive or
negative)
2) Direction (given by polarities)
What's another way to describe Amps? - Answers C/s
What are some examples of good conductors? - Answers - Copper
- Gold
- Silver (best)
- Platinum
Ammeters measure current flow from the _________ probe to the ________ probe within the meter.
- Answers Red; black
How do you measure current with an ammeter - Answers Break the wire and let current flow through
the meter
What do resistors do? - Answers Turn electrical energy to heat
What's the most common resistor? - Answers A carbon filament in an epoxy jacket
What's the charge on an electron? - Answers -1.6 e -19
How many e-'s are in -1C - Answers 6 e 18
Do birds land on transmission lines? Why or why not? - Answers No because they're too hot
(approximately 180 degrees F)
Do birds land on distribution lines? Why or why not? - Answers Yes because they're warm (85-95
degrees F)
What's the voltage of distribution lines? - Answers 100,000 MV
Are transmission lines insulated? - Answers No
Are distribution lines insulated? - Answers No
What's the amps of a typical wall socket? - Answers 15 A
Is it normal operating procedure for current to flow through the ground? - Answers No
What's the period of a wall socket? - Answers 1/60 seconds
Power is delivered if... - Answers The current flow is in the direction of the voltage rise
Power is absorbed if... - Answers The current flow is in the direction of the voltage drop
Power absorbed by a resistor must always be... - Answers Positive
A voltage source turned off becomes... - Answers A short circuit (a wire)
A current source turned off becomes... - Answers An open circuit (a broken wire)
The voltage across a capacitor must be... - Answers Continuous (if it was discontinuous, current
would be infinity at the discontinuity which is physically impossible)
i(t) = - Answers C(dv/dt)
How fast do electrons travel in a good conductor? What is this velocity called? - Answers 0.1 mm/s
drift velocity
The prongs on a typical grounded plug are more properly called what? What about the receptacle? -
Answers Blades and ground pin; Receptacle: slots and ground hole
What's the voltage of a typical wall socket in the U.S.? - Answers 120 V
Do birds land on distribution lines? Do they land on any wires? Explain why or why not. - Answers
Birds land on all cables, and particularly like the heat of distribution lines in the winter.
What's the meaning of the ground node in the node voltage analysis of a circuit. - Answers It's the
reference node and has 0V potential relative to itself.
How much current flows in a typical lightning bolt? - Answers on the order of 10 kA - 40 kA
What's the voltage of a car battery? How is it set up? - Answers 12 V
6 cells are connected in series, with 2 volts per cell
What is in one cell? - Answers - Sulfuric Acid (H2SO4) + water (electrolyte)
- 2 plates
----> 1 plate made of sponge lead
----> 1 plate made of lead dioxide
What does the chemical reaction of sulfuric acid on lead produce... - Answers Lead sulfate and e- are
liberated
Voltmeters measure the voltage drop from... - Answers The red probe to the black probe
Does the red probe connect to the positive or negative terminal? - Answers Positive
Does the black probe connect to the positive or negative terminal? - Answers Negative
A complete description of voltage requires which two things? - Answers 1) A value (positive or
negative)
2) Direction (given by polarities)
What's another way to describe Amps? - Answers C/s
What are some examples of good conductors? - Answers - Copper
- Gold
- Silver (best)
- Platinum
Ammeters measure current flow from the _________ probe to the ________ probe within the meter.
- Answers Red; black
How do you measure current with an ammeter - Answers Break the wire and let current flow through
the meter
What do resistors do? - Answers Turn electrical energy to heat
What's the most common resistor? - Answers A carbon filament in an epoxy jacket
What's the charge on an electron? - Answers -1.6 e -19
How many e-'s are in -1C - Answers 6 e 18
Do birds land on transmission lines? Why or why not? - Answers No because they're too hot
(approximately 180 degrees F)
Do birds land on distribution lines? Why or why not? - Answers Yes because they're warm (85-95
degrees F)
What's the voltage of distribution lines? - Answers 100,000 MV
Are transmission lines insulated? - Answers No
Are distribution lines insulated? - Answers No
What's the amps of a typical wall socket? - Answers 15 A
Is it normal operating procedure for current to flow through the ground? - Answers No
What's the period of a wall socket? - Answers 1/60 seconds
Power is delivered if... - Answers The current flow is in the direction of the voltage rise
Power is absorbed if... - Answers The current flow is in the direction of the voltage drop
Power absorbed by a resistor must always be... - Answers Positive
A voltage source turned off becomes... - Answers A short circuit (a wire)
A current source turned off becomes... - Answers An open circuit (a broken wire)
The voltage across a capacitor must be... - Answers Continuous (if it was discontinuous, current
would be infinity at the discontinuity which is physically impossible)
i(t) = - Answers C(dv/dt)
