Technician A says that Ohm's Law predicts that a conductor's resistance increases when amperage increases. Technician B says that Joule's Law predicts a small amount of resistance in a circuit becomes much greater when amperage increases. Who is correct?

Technician A says AC circuits are used in virtually all chassis circuits because a battery can easily store and supply AC current. Technician B says DC current is used to power hybrid drive electric motors. Who is correct?

Technician A says there are two theories of current flow: the electron theory and the conventional theory. Technician B says it is only important to remember that current flow is described by both concepts. Who is correct?

Which of the following electrical terms is most closely associated with 'electrical friction'?

Technician A says that the polarity of an electromagnet cannot be changed. Technician B says that the polarity of an electromagnet can be changed by reversing the polarity of current flow. Who is correct?

Alternators and generators both operate under what principle?

An important fact to remember about electromagnetic induction is that the strength of the magnetic field changes induces __________.

Technician A states that a battery can fail gradually due to sulfation on the plates. Technician B claims that a battery can fail gradually due to the loss of electrolyte. Who is correct?

Technician A says to always coat battery terminals with chassis grease to prevent corrosion. Technician B says that dielectric-type grease should be used instead because some types of chassis grease are electrically conductive. Who is correct?

Technician A says that the high-discharge amperage load test measures the ability of a battery to supply enough power during cranking, and the battery's capacity is tested based on its CCA rating. Technician B says that a battery must be 100% charged to perform a capacity test, so SOC must be first evaluated before proceeding. Who is correct?

Which of the following reasons best explains why a battery should be tested or replaced after an alternator or starting motor is replaced?

Which of the following conditions causes surface voltage leakage from a battery?

Which of the following conditions leads to hard sulfation of a battery?

Technician A says that conductance testing analyzes an alternating voltage signal after it has passed through a battery to determine its capacity. Technician B says that battery impedance to an AC signal is evaluated during conductance testing. Who is correct?

Consider performing three consecutive starter cranking cycles of 30 seconds with two-minute rest intervals between cycles. If batteries are correctly sized and no defects are present in the starter circuit or engine, battery voltage during cranking should not fall below:

Technician A says that all electric motors operate using principles of magnetic attraction and repulsion. Technician B says that, because unlike magnetic poles attract one another and like poles repel, it is possible to arrange magnetic poles within the motor to be continuously in a state of repulsion and attraction. Who is correct?

A starting motor should not be operated for longer than:

Technicians A and B are analyzing the results of a starter drive test on a starter circuit for a six-cylinder 855-cubic inch diesel engine. The engine cranks slowly and starter current draw is 1,250 amps. The battery voltage during cranking is 7.1 volts. Technician A says that the starter armature likely has an open winding. Technician B says that the results could be caused by damaged, oil-starved engine bearings. Who is correct?

When testing the starting system on a vehicle with a six-cylinder 855-cubic inch diesel engine, you find that the engine cranks slowly. The starter current draw is 90 amps, and the battery voltage during cranking is 12.1 volts. What should you do next?

After switching on all the lights and blower motors of a school bus, a belt squeal is heard. Technician A says that the belt tensioner spring could be broken. Technician B says that the belt is most likely worn. Who is correct?

Technician A says that today, the average 12-volt electrical system loads for a late-model highway tractor with an 84-amp average electrical load uses a 130-amp alternator. Technician B says that a much larger alternator than that is necessary to save fuel, last longer, and supply peak electrical loads at idle. Who is correct?

How many diodes are required to rectify one complete phase of stator AC output into DC?

Technician A says that a charging voltage of 16.0 volts for a few minutes after an engine starts on cold mornings is normal. Technician B says that a charging voltage of 16.0 volts for a few minutes is likely caused by a poor ground or defective voltage regulator. Who is correct?

Which of the following ratios is the most typical drive-pulley ratio for an alternator used with on-highway heavy-duty diesel engines?

Technician A says that multimeters are electrical measuring instruments combining functions of at least voltage, resistance, and amperage measurement into a single compact instrument. Technician B says that digital multimeters are the most common category of multimeters and provide numerical displays of electrical data. Who is correct?

Which electrical service tool is best used to locate a broken wire behind a body panel?

Technician A says that circuit tracers, also called wire tracers, are electronic service tools used to trace a single wire over a distance to check for shorts, or open circuits. Technician B says that circuit tracers can identify broken wires deeply buried behind walls or in tightly bundled harnesses. Who is correct?

How is the strength of a magnetic field sensed when measuring DC amperage?

A test light illuminates when connected between a chassis ground and the grounded metal case of a blower motor that is switched on. Which of the following best describes the circuit's condition?

Technician A says that adding a set of fog lights to the same circuit as the high/low-beam headlights requires increasing the amperage of the circuit protection device to prevent the circuit from being overloaded. Technician B says that the diameter of the wiring likely must increase and the headlight circuit wiring needs replacement. Who is correct?

Fuses prevent damage to wiring by:

Wire gauge is a measurement of:

Which type of diagram is commonly used by North American manufacturers to locate a wiring connection in the electrical system?

What is the purpose of current tracks?

Consider a series circuit supplied with 12 volts. It has three loads. The voltage drop across the first two loads is 3 and 4 volts, respectively. What is the voltage drop across the third load?

Technician A says that adding more loads to a series circuit increases the amperage used by the circuit. Technician B says adding more loads to a parallel circuit increases the amperage flowing through a circuit. Who is correct?

Which type of circuit breaker must be reset by depressing a reset button?

When electrical current begins to move in a basic electrical circuit, where does electron flow take place?

Which of the following takes place in a series circuit when more loads are added to the circuit?

What type of resistor most likely controls current flow through a heater/AC blower motor?

Which of the following activates a manual control switch?

Which type of circuit control device most likely indicates whether the linkage of a bus door has properly closed?

Technician A says that a frequent cause of failure of a pull-in winding of a solenoid is misadjusted linkage. Technician B says solenoid failure is most often caused by incorrectly connected pull-in and hold-in windings. Who is correct?

Which of the following switches has a single throw?

What is the primary function of a capacitor in an electrical circuit?

Which of the following components is used to protect a circuit from excessive current?

Technician A says that a diode allows current to flow in one direction only. Technician B says that a diode can be used to convert AC to DC. Who is correct?

Technician A says that a relay is used to control a high-current circuit with a low-current signal. Technician B says that a relay can be used to isolate different parts of a circuit. Who is correct?

Technician A says that a voltmeter measures the potential difference between two points in a circuit. Technician B says that an ammeter measures the current flow through a circuit. Who is correct?