USPS 955 TEST QUESTIONS WITH CORRECT
ANSWERS 2026
State Ohm's law - CORRECT ANSWER -V=IXR
R=V/I
I=V/R
If current goes down, what does resistance do? - CORRECT ANSWER -Reistance goes up
If Voltage is CONSTANT and Resistance goes DOWN, what must Current do? - CORRECT ANSWER
-Current HAS to go UP!
What is the definition of a short circuit? - CORRECT ANSWER -Zero resistance. Circuit has high
current, and zero resistance.
What would cause Current to DECREASE in a circuit, IF Voltage remained CONSTANT? - CORRECT
ANSWER -INCREASSE in Resistance
What is a Transformer? - CORRECT ANSWER -An electrical device that transfers energy from one
electrical circuit to another by magnetic coupling, aka: Mutal Induction. One set of windings
induce a voltage in the other set of windings.
What are Transformers used for? - CORRECT ANSWER -Used to convert between high and low
voltages and for impedance transformation.
State the Power formula. - CORRECT ANSWER -P = V X I
power equals voltage times current
, What are air core transformers main use? - CORRECT ANSWER -Radio frequency circuits ABOVE
20kHz
What are iron core transformers main use? - CORRECT ANSWER -Lower frequency: below 20kHz
To transmit electrical power what must a transformer have? - CORRECT ANSWER -Has a very
high current OR very high voltage. High current means a high flow rate of electrons. This
requires a VERY large COPPER or ALUMINUM cable.
*How does a Power Station function? - CORRECT ANSWER -Uses high voltage to reduce the
amount and weight and therefore
What is the symbol for a transformer? - CORRECT ANSWER -XX
What kind of electrical charge does a neutron have? - CORRECT ANSWER -Neutral
What kind of electrical charge does a proton have? - CORRECT ANSWER -Positive
The step down transformer outside a house does what? - CORRECT ANSWER -Reduces the
voltage to a usable voltage for the house ELECTRIC, which are usually TWO 120VAC legs.
What is an electronic shunt? - CORRECT ANSWER -A device which allows electric current to pass
around a point in a circuit. A shunt as CIRCUIT PROTECTION: is a device that is commonly called
a CROWBAR circuit and is used when a circuit must be protected from over VOLTAGE.
What does a capacitor do? - CORRECT ANSWER -When used as a shunt, redirects hight
frequency nouse to ground before it can transmit to the load or other circuit components. This
is why they are used so frequently in DC power supplies as AC filters.
ANSWERS 2026
State Ohm's law - CORRECT ANSWER -V=IXR
R=V/I
I=V/R
If current goes down, what does resistance do? - CORRECT ANSWER -Reistance goes up
If Voltage is CONSTANT and Resistance goes DOWN, what must Current do? - CORRECT ANSWER
-Current HAS to go UP!
What is the definition of a short circuit? - CORRECT ANSWER -Zero resistance. Circuit has high
current, and zero resistance.
What would cause Current to DECREASE in a circuit, IF Voltage remained CONSTANT? - CORRECT
ANSWER -INCREASSE in Resistance
What is a Transformer? - CORRECT ANSWER -An electrical device that transfers energy from one
electrical circuit to another by magnetic coupling, aka: Mutal Induction. One set of windings
induce a voltage in the other set of windings.
What are Transformers used for? - CORRECT ANSWER -Used to convert between high and low
voltages and for impedance transformation.
State the Power formula. - CORRECT ANSWER -P = V X I
power equals voltage times current
, What are air core transformers main use? - CORRECT ANSWER -Radio frequency circuits ABOVE
20kHz
What are iron core transformers main use? - CORRECT ANSWER -Lower frequency: below 20kHz
To transmit electrical power what must a transformer have? - CORRECT ANSWER -Has a very
high current OR very high voltage. High current means a high flow rate of electrons. This
requires a VERY large COPPER or ALUMINUM cable.
*How does a Power Station function? - CORRECT ANSWER -Uses high voltage to reduce the
amount and weight and therefore
What is the symbol for a transformer? - CORRECT ANSWER -XX
What kind of electrical charge does a neutron have? - CORRECT ANSWER -Neutral
What kind of electrical charge does a proton have? - CORRECT ANSWER -Positive
The step down transformer outside a house does what? - CORRECT ANSWER -Reduces the
voltage to a usable voltage for the house ELECTRIC, which are usually TWO 120VAC legs.
What is an electronic shunt? - CORRECT ANSWER -A device which allows electric current to pass
around a point in a circuit. A shunt as CIRCUIT PROTECTION: is a device that is commonly called
a CROWBAR circuit and is used when a circuit must be protected from over VOLTAGE.
What does a capacitor do? - CORRECT ANSWER -When used as a shunt, redirects hight
frequency nouse to ground before it can transmit to the load or other circuit components. This
is why they are used so frequently in DC power supplies as AC filters.
