Question 1

Technician A says electrical circuits have an electrical pressure (force)that is used to move electrons through a circuit. Technician B says a lack of resistance in an electrical device (load)will prevent work being performed to the extent it was designed. Who is correct?

Accepted Answer

Both technicians are correct. Electrical circuits require a force to move electrons through the circuit, which is known as electrical pressure or voltage. Additionally, electrical devices or loads are designed to perform work, and a lack of resistance can prevent the device from performing to its full potential. Therefore, both A and B are correct.

Question 2

Technician A says that friction between the vehicles tires and the road is one factor in stopping the vehicle. Technician B says that a car with locked brakes stops in the shortest time possible. Who is correct?

Accepted Answer

Technician A is correct in stating that friction between the vehicle's tires and the road is one factor in stopping the vehicle. This is because the friction between the tires and the road creates a force that opposes the motion of the vehicle, which helps to slow it down. Technician B is incorrect because a car with locked brakes does not stop in the shortest time possible. When the brakes are locked, the wheels cannot rotate, which reduces the friction between the tires and the road. This can actually increase the stopping distance and time, especially in wet or slippery conditions. The shortest stopping distance is achieved when the brakes are applied just enough to slow the wheels without locking them.

Question 3

Technician A says kinetic friction changes kinetic energy into thermal energy. Technician B says static friction holds the car in place when it is stopped. Who is correct?

Accepted Answer

Both technicians are correct. Kinetic friction acts between two surfaces that are in motion relative to each other and converts kinetic energy into thermal energy. Static friction, on the other hand, acts between two surfaces that are not in relative motion and holds the car in place when it is stopped.

Question 4

Technician A says the relationship of voltage, current, and resistance is summarized by a mathematical equation known as Ohm's law. Technician B says Ohm's law states that one ampere is required to push one volt through a resistance of one Ohm. Who is correct?

Accepted Answer

Ohm's law is a mathematical equation that describes the relationship between voltage, current, and resistance, expressed as V = IR. Technician B's statement is incorrect because Ohm's law does not define the units of measurement in that way.

Question 5

Brake fade is being discussed. Technician A says a thin layer of gas between the pads or linings and the rotors could cause brake fading. Technician B says heat is the greatest cause of brake fade. Who is correct?

Accepted Answer

Both technicians are partially correct. A thin layer of gas can cause brake fade, but heat is the primary cause. Combining both explanations is the best answer.

Question 6

Technician A hydraulic fluid can transmit motion and force because a fluid cannot be compressed. Technician B says mechanical advantage in a hydraulic system is proportional to the size of the input piston versus the output piston. Who is correct?

Accepted Answer

Technician A is correct in stating that hydraulic fluid transmits motion and force because it cannot be compressed. This means that the force applied to the input piston is transferred to the output piston without any loss due to compression of the fluid. 
Technician B is also correct in stating that the mechanical advantage in a hydraulic system is proportional to the size difference between the input and output pistons. The larger the output piston, the greater the force that can be exerted, while the smaller input piston requires less force to be applied. Therefore, the ratio of the area of the output piston to the area of the input piston determines the mechanical advantage of the system.

Question 7

All of the following are types of brake fade EXCEPT:

Accepted Answer

Brake fade refers to the reduction in braking power, and it can be caused by various factors such as gas buildup between the brake pads and rotors (gas fade), overheating of the brake components leading to a decrease in friction (lining fade), or the breakdown of mechanical parts. However, "drum" is not a type of brake fade; it refers to a component of the brake system, specifically a type of brake used in some vehicles.

Question 8

Brake operational theories are being discussed. Technician A says an object at rest creates kinetic energy. Technician B says kinetic friction is created when the brakes are applied. Who is correct?

Accepted Answer

The answer of Brake operational theories are being discussed. Technician...

Question 9

Technician A says that inertia is best described as the resistance to a change in motion.   Technician B says that momentum is the force of continuing motion. Who is correct?

Accepted Answer

Inertia is indeed the resistance to a change in motion, as described by Technician A. Meanwhile, momentum is the product of an object's mass and velocity, and can be described as the force of continuing motion, as stated by Technician B. Therefore, both Technician A and Technician B are correct.

Question 10

In a sealed hydraulic system, brake fluid is pressurized to:

Accepted Answer

In a sealed hydraulic system, brake fluid is pressurized to transmit force, pressure, and movement. The pressurized fluid acts on various components to facilitate the braking process, effectively transmitting the driver's input (force) through pressure, which in turn causes movement in the brake mechanisms.

Question 11

Technician A says the energy used by the braking system is based on the kinetic energy, mass, weight, and speed of the vehicle and its braking system. Technician B says the amount of friction in a brake system depends on the pressure (force)exerted on the friction components and the surface area?

Accepted Answer

Both technicians are correct. Technician A is describing the basic physics behind the energy of motion, and technician B is describing the factors that govern how much friction is created by a brake system. Therefore, choice C, both A and B, is the correct answer.

Question 12

Technician A says that mass is the measurement of gravity acting on an object. Technician B says that weight is the measurement of the number of molecules that make up an object. Who is correct?

Accepted Answer

Technician A is incorrect because mass is a measure of the amount of matter in an object, not the measurement of gravity acting on an object. Technician B is incorrect because weight is the force exerted by gravity on an object, not the measurement of the number of molecules that make up an object.

Question 13

Brake friction materials are being discussed. Technician A says molding bits of metal into a brake lining produces an excellent friction material. Technician B says composite linings can be made from synthetic fibers bonded together. Who is correct?

Accepted Answer

Both statements are correct. Molding bits of metal into a brake lining does produce an excellent friction material due to the durability and heat resistance of metal. Composite linings made from synthetic fibers bonded together are also used in brake systems, offering benefits like reduced weight and cost, as well as good performance under a variety of conditions.

Question 14

Technician A says reducing the coefficient of friction lowers the amount of force needed to move an object. Technician B says coefficient of friction is the relationship of tensile force to weight. Who is correct?

Accepted Answer

The answer of Technician A says reducing the coefficient of...

Question 15

Brake friction materials are being discussed. Technician A says semi-metallic materials are made from a mix of organic or synthetic fibers and metals molded together. Technician B says ceramic pads provide suitable life, provide good stopping, and reduce changes of fading, but they retain heat. Who is correct?

Accepted Answer

Both technicians are correct. Technician A accurately describes semi-metallic materials, and Technician B correctly describes the advantages and disadvantage of ceramic pads.

Question 16

Mass is being discussed. Technician A says that the mass of an object is equal to the weight of an object. Technician B says that mass is not the weight of the object but the amount of matter in that object. Who is correct?

Accepted Answer

Technician B is correct. Mass is a fundamental property of matter, referring to the amount of matter in an object. Weight, on the other hand, refers to the force of gravity acting on an object's mass. So while weight can vary depending on the object's location, mass remains the same regardless of location.

Question 17

Brake systems are being discussed. Technician A says the service brakes may be drum or disc. Technician B says ABS becomes involved only if it senses one (or more)wheels about to lock up. Who is correct?

Accepted Answer

Both technicians are correct. Service brakes can be either drum or disc, and ABS does become involved only if it senses one or more wheels about to lock up.

Question 18

Technician A says to calculate the coefficient of friction, measure the force required to slide an object over a surface and then divide it by the weight of the object. Technician B says the moving force that slides an object over a surface is tensile force. Who is correct?

Accepted Answer

The answer of Technician A says to calculate the coefficient...

Question 19

Technician A says the weight of a car is not distributed evenly on all four wheels even when the vehicle is standing still. Technician B says front brake systems are smaller than rear units. Who is correct?

Accepted Answer

Technician A is correct because the weight distribution of a car is not evenly spread across all four wheels due to the engine's placement and other factors, leading to variations in weight on each wheel. Technician B is incorrect because front brake systems are typically larger than rear units to accommodate the higher braking load on the front wheels during deceleration.

Question 20

An electrical circuit using 12 volts and having 10 ohms of resistance would have a current of:

Accepted Answer

Using Ohm's Law, which is I = V/R (where I is current in amperes, V is voltage in volts, and R is resistance in ohms), the current can be calculated as I = 12V / 10Ω = 1.2 amperes.

Quiz 2: Principles and Theories of Operation

Technician A says electrical circuits have an electrical pressure (force) that is used to move electrons through a circuit. Technician B says a lack of resistance in an electrical device (load) will prevent work being performed to the extent it was designed. Who is correct?