FREE Ramsay Maintenance Question and Answers
A _____ is used to stop an AC solenoid from "humming."
The direction of the current can change up to 60 times per second when an AC current is used to activate it, alternating between positive and negative peaks. As a result, the current decreases to zero 60 times per second, and as a result, the magnetic field within the solenoid also drops 60 times per second (because the magnetic field is proportional to the current). As a result, many times per second, the return spring's actuating force temporarily exceeds that of the solenoid. This motion causes the armature to vibrate continuously, which increases the stress on the solenoid's components and produces a buzzing sound.
A shading ring can resolve this issue. The ring, a tiny, electrically conductive ring typically formed of copper, produces a magnetic field that is 90 degrees out of phase with the solenoid's own magnetic field, holding the armature in place when the current occasionally falls to zero.
Why would you utilize the 'delayed sweep' setting on an oscilloscope?
When you need to examine a small portion of a waveform in more detail, utilize the oscilloscope's "delayed sweep" mode. It gives a more detailed look of that portion of the waveform by allowing you to choose a time "window" and display it on a much larger scale.
What does 'bulk modulus' mean in a hydraulic system?
A substance's bulk modulus gauges its resistance to compression. It is employed in hydraulic systems to take into account the fact that, while being widely thought of as being incompressible, hydraulic fluids do display some compressibility, which can have an impact on system performance.
When installing components in a pneumatic system, the proper order is:
The Filter, Regulator, and Lubricator unit, also referred to as the FRL unit, is made to filter the air leaving the compressor before it enters the system.
The lubricator produces an air and oil mist to lubricate the system's components, enhancing their performance and extending their useful lives. The filter purges the air of small particles and contaminants, the regulator delivers air at a predetermined, constant pressure, and the lubricator supplies air.
In order to prevent contaminated or lubricating oil particles from impairing the regulator's function, the filter must be put before the regulator, which must then be installed before the lubricator. Additionally, the filter is put in place before the lubricator to prevent the air from being filtered of oil particles.
Which of the following most accurately sums up the idea of "Critical Speed" in the context of rotating machinery maintenance?
The critical speed is the speed at which resonance occurs in rotating machinery. At this speed, vibration amplitude greatly rises, perhaps causing damage. In practice, operating machinery nearย its critical speed is often discouraged.
A sequence of states must be stored in the control process of a system using a Programmable Logic Controller (PLC). Which PLC programming language among the following would be most suited for this task?
The graphical programming language Sequential Function Chart (SFC), which is used to program PLCs, is especially well suited for planning and specifying a sequence of states or phases in the control process. It is the best option for this situation since it offers a structured flowchart approach and is useful in displaying the order of steps in a process.
How does the Reynolds number affect the flow conditions in a fluid power system?
When predicting the change from laminar to turbulent flow, fluid mechanics uses the Reynolds number, a dimensionless variable.
Megohmmeters are typically employed to measure:
Megohmmeters are ohmmeters, which measure resistance on a scale of megohms. They can measure very high resistances (millions of ohms). As a result, they are employed to test materials with extremely high electrical resistance, such as insulation.
The power storage component of an Uninterruptible Power Supply (UPS) system is largely in charge of supplying electricity in the event of a mains outage. Which of the following power storage technologies is most suited for high-performance UPS applications because it can provide high energy density and quick charging?
In comparison to other battery technologies, lithium-ion batteries offer a high energy density and can be charged quite quickly. Because of this, they are appropriate for high-performance UPS applications where a sizable amount of energy must be stored and promptly retrieved during a power loss.
Emitter-base junctions in transistors require forward bias in order for the transistor to operate. As a result, the base of PNP transistors is _________ with respect to the emitter.
The base, emitter, and collector are the three terminals that make up a transistor. As a result, a transistor has connections between its base and emitter, base and collector, and collector and emitter. A particular voltage must be delivered to the base-collector junction in order to turn on a transistor. To turn on the terminal in a PNP circuit, the base needs to be at a lower voltage than the emitter. To put it another way, the base should be negative toward the transmitter.
A neutral, carburizing, and oxidizing flame differ from one another due to:
The acetylene-oxygen content of each flame is what distinguishes the three flames from one another. The exact ratio required for combustion is present in a neutral flame. The neutral flame serves only as a heater and has no impact on the welded metal.
The extra acetylene in the carburizing flame leads the welded metal to absorb carbon.
The extra oxygen in the oxidizing flame causes the welded metal to oxidize. It is mostly used for non-ferrous metals like bronze and copper due to its oxidizing action.
Why should an oil separator and compressor be used together in a refrigeration system?
In the refrigeration system, an oil separator is a tool used to remove oil from the refrigerant gas. Although oil is necessary to lubricate the compressor, any oil that enters the refrigerant circuit might compromise the system's performance by coating the heat exchanger surfaces and hindering heat transmission. Toย reduce the amount of oil that can enter the refrigerant circuit, an oil separator is used.
Which of the following machines is the splash method of lubrication advised for?
The interior components of the mechanism are lubricated by a mist of oil that is mechanically splashed up from pans or trays in the crankcase in the splash lubrication system. The oil level in the crankcase will have a significant impact on the lubrication level, making the splash approach problematic. A high oil level may result in excessive lubrication, whilst a low oil level will result in insufficient lubrication. Splash technique lubrication is therefore limited to extremely tiny engines, like lawnmowers.
How do the speed and torque of the output shaft depend on the gear ratio when establishing a power transmission system?
The ratio of the input gear's rotating speed to the output gear's rotational speed is known as the gear ratio in a mechanical drive system. Higher gear ratios result in a decrease in output speed and an increase in torque.
What purpose does a hydraulic accumulator fulfill in a system?
A hydraulic accumulator uses hydraulic fluid that is under pressure to store energy. Its major job is to keep the system's pressure constant when the pump isn't working or when demand is at its highest.
Intermittent welding has the benefit of being:
Please select 2 correct answers
The fillet weld is done intermittently while using the intermittent welding joint welding technique. In addition to being more cost-effective (as less energy and materials are needed), it is also simpler to repair. Because the welding is not continuous, if it fails, just a tiny portion of the material will be damaged before the stress is released, making the damage easier to fix. If the welding had been continuous, the entire junction would have been destroyed and would have needed to be rewelded.
Intermittent welding, by definition, is weaker than full welding.