MECP PRACTICE EXAM QUESTIONS &
ANSWERS 2024/2025
To find voltage drops on Amplifier grounds, what setting should be used on the DMM while loading
down and testing between the amplifier ground and the vehicles chassis ground point? - ANSWERSDC
volts
If an insufficient ground in an amplifier and is measured under load (i.e. While typical current is flowing),
it will show a difference of potential between which points listed? - ANSWERSBetween the (-) negative
battery post and the (-) negative input of the amplifier
Kirchhoff's Voltage Law (KVL) states which one of the following? - ANSWERSThe voltage applied to a DC
series circuit must equal the sum of the voltage drops within the circuit .
Inductors used in aftermarket mobile audio systems perform which one of the functions listed as their
primary purpose? - ANSWERSOppose a change in current flow
When wiring multiple relays to trigger from a single low current output, how many 80 ohm coil relays
can safely be connected at 12 volts if that output that supplies 500mA current? - ANSWERS3
Resistors used in aftermarket mobile audio systems perform which one of the functions listed their
primary purpose? - ANSWERSOppose current flow.
What electrical unit expresses difference of potential in an electrical circuit? - ANSWERSVolts
As car batteries age, their internal impedance drops. - ANSWERSFalse
A resistor with a value of 6.6K Ohm is an abbreviation for which value? - ANSWERS6600 Ohms
, How much electrical power consumption results from measured values of 14 volts and 8 amps? -
ANSWERS112 Watts
What type of electronic component has emitter, collector, and base terminals? - ANSWERSNPN
Transistor
AC ripple in a healthy automotive alternator is highest at idle (roughly 800 to 1000 RPM). -
ANSWERSFalse
What is the measured voltage on two 12v batteries connected in parallel as pictured? - ANSWERS12volts
If a diode is operating normally in a forward biased condition....? - ANSWERSPositive current on the
anode flows to the cathode
An inductance value of 1 Henry is equal to how many milliHenries (mH)? - ANSWERS1000 mH
An inductance value of 1 Henry is equal to how many milliHenries (mH)? - ANSWERS1000 millihenry
Which two terminals shown in the diagram of an SPDT automotive relay are the coil terminals? -
ANSWERSA and E
Which two terminals shown in the diagram are the Normally Open and Common terminals of an SPDT
automotive relay? - ANSWERSB and D
Rectification of AC in a standard automotive alternator involves how many phases of AC? - ANSWERS3
phases
What is the name for the side of a silicone diode with the line on it? - ANSWERSCathode
How is a fuse connected in an automotive D.C. electrical circuit? - ANSWERSIn series between the
voltage source and the load
ANSWERS 2024/2025
To find voltage drops on Amplifier grounds, what setting should be used on the DMM while loading
down and testing between the amplifier ground and the vehicles chassis ground point? - ANSWERSDC
volts
If an insufficient ground in an amplifier and is measured under load (i.e. While typical current is flowing),
it will show a difference of potential between which points listed? - ANSWERSBetween the (-) negative
battery post and the (-) negative input of the amplifier
Kirchhoff's Voltage Law (KVL) states which one of the following? - ANSWERSThe voltage applied to a DC
series circuit must equal the sum of the voltage drops within the circuit .
Inductors used in aftermarket mobile audio systems perform which one of the functions listed as their
primary purpose? - ANSWERSOppose a change in current flow
When wiring multiple relays to trigger from a single low current output, how many 80 ohm coil relays
can safely be connected at 12 volts if that output that supplies 500mA current? - ANSWERS3
Resistors used in aftermarket mobile audio systems perform which one of the functions listed their
primary purpose? - ANSWERSOppose current flow.
What electrical unit expresses difference of potential in an electrical circuit? - ANSWERSVolts
As car batteries age, their internal impedance drops. - ANSWERSFalse
A resistor with a value of 6.6K Ohm is an abbreviation for which value? - ANSWERS6600 Ohms
, How much electrical power consumption results from measured values of 14 volts and 8 amps? -
ANSWERS112 Watts
What type of electronic component has emitter, collector, and base terminals? - ANSWERSNPN
Transistor
AC ripple in a healthy automotive alternator is highest at idle (roughly 800 to 1000 RPM). -
ANSWERSFalse
What is the measured voltage on two 12v batteries connected in parallel as pictured? - ANSWERS12volts
If a diode is operating normally in a forward biased condition....? - ANSWERSPositive current on the
anode flows to the cathode
An inductance value of 1 Henry is equal to how many milliHenries (mH)? - ANSWERS1000 mH
An inductance value of 1 Henry is equal to how many milliHenries (mH)? - ANSWERS1000 millihenry
Which two terminals shown in the diagram of an SPDT automotive relay are the coil terminals? -
ANSWERSA and E
Which two terminals shown in the diagram are the Normally Open and Common terminals of an SPDT
automotive relay? - ANSWERSB and D
Rectification of AC in a standard automotive alternator involves how many phases of AC? - ANSWERS3
phases
What is the name for the side of a silicone diode with the line on it? - ANSWERSCathode
How is a fuse connected in an automotive D.C. electrical circuit? - ANSWERSIn series between the
voltage source and the load
