1.
Tech A says you can measure up to 100 amps directly through the meter. Tech B says when checking high volts, you need to use a volt clamp so you don't damage the digital volt-ohmmeter (DVOM). Who is correct?
Correct Answer
D. Neither Tech A nor B
Explanation
Neither Tech A nor Tech B is correct. Tech A is incorrect because most meters can only measure up to a certain amperage, typically much lower than 100 amps. For higher amperage measurements, a clamp meter or a current transformer should be used. Tech B is also incorrect because a digital volt-ohmmeter (DVOM) is designed to measure voltage and resistance, not high currents. To measure high voltage, a high voltage probe or a specialized meter should be used.
2.
Tech A says when checking resistance in a circuit, you need to have power connected to the component. Tech B says ideally, you should have a component disconnected. Who is correct?
Correct Answer
B. Tech B
Explanation
Tech B is correct. When checking resistance in a circuit, it is ideal to have the component disconnected. This is because if the component is connected to power, it may affect the resistance reading and provide inaccurate results. Disconnecting the component ensures that there is no interference from other parts of the circuit, allowing for a more accurate measurement of resistance.
3.
Tech A says Ohm's law will show how many amps are needed in a circuit with 110-ohm resistor and a 12-volt power supply. The amps needed are:
Correct Answer
C. 0.12 amps.
Explanation
Tech A is correct. Ohm's law states that the current (in amps) flowing through a circuit is equal to the voltage (in volts) divided by the resistance (in ohms). In this case, the voltage is 12 volts and the resistance is 110 ohms. Therefore, the current needed in the circuit can be calculated as 12 volts divided by 110 ohms, which equals 0.109 amps or approximately 0.11 amps. Rounded to two decimal places, the answer is 0.12 amps.
4.
What materials make a good insulator?
Correct Answer
B. Ceramic and plastic
Explanation
Ceramic and plastic are good insulators because they have high resistivity, meaning they do not allow the flow of electric current easily. They have a molecular structure that does not allow the movement of electrons, preventing the transfer of heat or electricity. Copper and aluminum, on the other hand, are good conductors of electricity and heat, so they are not good insulators. Therefore, the correct answer is Ceramic and plastic.
5.
_____________ is/are fundamental to the automobile.
Correct Answer
D. All of the above
Explanation
All of the options listed (a 12-volt storage battery, an engine starting system, and a charging system) are fundamental components of an automobile. A 12-volt storage battery is necessary to power the electrical systems and start the engine. The engine starting system is essential for initiating the combustion process and getting the engine running. The charging system ensures that the battery remains charged and ready for use. Therefore, all of these components are crucial for the proper functioning of an automobile.
6.
The traditional automobile battery type is the:
Correct Answer
A. Lead acid.
Explanation
The traditional automobile battery type is lead acid. Lead acid batteries have been used in automobiles for many years due to their reliability, affordability, and ability to provide high starting currents. They consist of lead plates immersed in an electrolyte solution of sulfuric acid, which allows for the conversion of chemical energy into electrical energy. This type of battery is still widely used in vehicles today, although newer technologies such as lithium-ion are starting to gain popularity.
7.
The nominal voltage of each cell of a battery is _____________ volts.
Correct Answer
C. 2.1
Explanation
The nominal voltage of each cell of a battery is typically 2.1 volts. This is the standard voltage that is expected from a single cell in a battery.
8.
The following battery has removable cell covers.
Correct Answer
C. Lead acid flooded cell
Explanation
Lead acid flooded cell batteries have removable cell covers, allowing for easy access to the individual cells for maintenance and replacement. Sealed batteries, on the other hand, do not have removable cell covers as they are designed to be maintenance-free and prevent any leakage of electrolyte. Therefore, the correct answer is Lead acid flooded cell.
9.
A technician must always wear ______________ when working on a battery.
Correct Answer
D. Safety glasses
Explanation
Safety glasses are necessary when working on a battery to protect the technician's eyes from any potential hazards such as acid splashes or debris. Wearing designer clothes, earrings, or tennis shoes does not provide any form of protection for the eyes and would not be suitable for this task.
10.
Tech A says that batteries should be disposed of in landfills. Tech B says that batteries must be recycled. Who is correct?
Correct Answer
B. Tech B
Explanation
Tech B is correct because batteries should be recycled. Batteries contain harmful chemicals and heavy metals that can contaminate the environment if disposed of in landfills. Recycling batteries allows these materials to be safely extracted and reused, reducing pollution and conserving resources. Therefore, it is important to follow proper battery recycling practices to protect the environment.
11.
Tech A says that the starter converts mechanical energy to electrical energy. Tech B says that the starter converts electrical energy to mechanical energy. Who is correct?
Correct Answer
B. Tech B
Explanation
Tech B is correct. The starter in a vehicle is an electric motor that converts electrical energy from the battery into mechanical energy to start the engine. It uses this mechanical energy to crank the engine and get it running. Therefore, Tech B's statement accurately describes the function of the starter.
12.
Tech A says that the alternator converts electrical energy into mechanical energy. Tech B says that the alternator converts mechanical energy into electrical energy. Who is correct?
Correct Answer
A. Tech A
Explanation
Tech A is correct because an alternator is a device that converts mechanical energy into electrical energy. It does this by using a rotating magnetic field to induce an alternating current in the stator windings. This electrical energy can then be used to power the electrical systems of a vehicle or to charge the battery. Tech B is incorrect in stating that the alternator converts mechanical energy into electrical energy.
13.
The _____________ monitors battery voltage and varies current flow through the rotor field circuit.
Correct Answer
C. Voltage regulator
Explanation
The voltage regulator is responsible for monitoring the battery voltage and adjusting the current flow through the rotor field circuit. It ensures that the battery voltage remains within the desired range and regulates the amount of current flowing to the rotor, which in turn controls the output voltage of the generator or alternator. The voltage regulator plays a crucial role in maintaining a stable electrical system by preventing overcharging or undercharging of the battery.
14.
The process of converting alternating current (AC) into direct current (DC) is called:
Correct Answer
A. Rectification.
Explanation
Rectification is the process of converting alternating current (AC) into direct current (DC). This is achieved by using a device called a rectifier, which allows current to flow in only one direction. Rectification is important in many electrical applications, such as power supplies and electronic devices, where a steady and constant flow of current is required. Electromotive force (EMF) and counter-electromotive force (CEMF) are related to the generation of electrical voltage, but they do not specifically refer to the conversion of AC to DC. Recertification is unrelated to the process of converting AC to DC.
15.
The ______________ allows current to flow one way in the rectifier assembly.
Correct Answer
A. Diode
Explanation
A diode is a semiconductor device that allows current to flow in one direction and blocks it in the opposite direction. In a rectifier assembly, the diode is used to convert alternating current (AC) into direct current (DC) by allowing current to flow only in one direction. The other options, such as thyroid, electromotive force (EMF), and counter-electromotive force (CEMF), are not related to the function of a rectifier assembly in allowing current to flow one way.
16.
Tech A says that to do a quick test on an alternator charging system is to remove one of the cables off the battery posts, and if the engine continues to run, then the charging system is good. Tech B says that the practice of removing a battery cable connection can damage the electronics on the vehicle. Who is correct?
Correct Answer
B. Tech B
Explanation
Tech B is correct. Removing a battery cable connection can indeed damage the electronics on the vehicle. When the cable is disconnected, it can cause a voltage spike that can harm sensitive electronic components. Additionally, disconnecting the battery can also reset certain settings and parameters in the vehicle's computer system, leading to potential issues with the vehicle's performance. Therefore, it is not recommended to test the alternator charging system by removing a battery cable.
17.
On modern vehicles, what replaced the voltage regulator?
Correct Answer
A. Power train control module (PCM) or body control module (BCM)
Explanation
The voltage regulator on modern vehicles has been replaced by the power train control module (PCM) or body control module (BCM). These modules are responsible for controlling various functions and systems in the vehicle, including the regulation of voltage to ensure proper operation of electrical components. The PCM or BCM monitors the electrical system and adjusts the voltage as needed, eliminating the need for a separate voltage regulator.
18.
Tech A says that the standard 12-volt car battery has 3 cells with 4.2 volts in each cell. Tech B says that the standard 12-volt car battery has 4 cells with 3.3 volts each. Who is correct?
Correct Answer
D. Neither Tech A nor B
Explanation
Neither Tech A nor Tech B is correct. A standard 12-volt car battery typically consists of 6 cells, each with a voltage of around 2.1 volts. So, neither Tech A's claim of 3 cells with 4.2 volts each, nor Tech B's claim of 4 cells with 3.3 volts each is accurate.
19.
Tech A says that failure of a battery hold down can cause battery plate damage. Tech B says that a bungee cord is a suitable battery hold down. Who is correct?
Correct Answer
A. Tech A
Explanation
Tech A is correct. The failure of a battery hold down can indeed cause battery plate damage. A battery hold down is designed to secure the battery in place and prevent it from moving or vibrating excessively. If the hold down fails, the battery can become loose and move around, potentially causing damage to the battery plates. On the other hand, Tech B is incorrect in stating that a bungee cord is a suitable battery hold down. Bungee cords are not specifically designed for this purpose and may not provide adequate stability and security for the battery.
20.
Tech A says high resistance causes an increase in current flow. Tech B says a voltage drop is another name for high resistance. Who is correct?
Correct Answer
D. Neither Tech A nor B
Explanation
Tech A is incorrect because high resistance actually reduces current flow, according to Ohm's Law (I = V/R), where I is current, V is voltage, and R is resistance. As resistance increases, current decreases.
Tech B is incorrect because a voltage drop is not another name for high resistance. A voltage drop occurs when there is a resistance in a conductor, causing a decrease in voltage along the path. High resistance contributes to voltage drops, but they are not synonymous.