Magnetic Particle Testing: Principles and Practice Quiz

Magnetic particles are available in different colors for both A and B. The first reason is for color contrast with the part surface, which makes it easier to see the magnetic particles and any indications or defects on the surface. The second reason is to enhance the detection of indications, as different colors can provide better visibility and contrast depending on the type of part being inspected. Therefore, both reasons contribute to the availability of magnetic particles in different colors.

When selecting a powder to be used as a magnetic particle medium, it is important to choose a powder that provides a high contrast to the surface being tested. This is because a high contrast allows for better visibility and detection of any defects or cracks on the surface. A powder with low contrast would make it difficult to distinguish between the magnetic particles and the surface, leading to potential missed defects. Adherence to the surface being tested and the requirement of a high demagnetization current are not prime considerations when selecting the powder.

The correct answer is "Lifting test. The AC yoke must lift at least 4.5 kg (10 lbs)." This answer states that the performance of an AC yoke is measured through a lifting test, where the yoke must be able to lift a minimum weight of 4.5 kg (10 lbs).

The right hand rule is a rule used to determine the direction of current flow in a conductor when lines of magnetic force surround it. By pointing the thumb of the right hand in the direction of the current flow, the fingers will curl in the direction of the magnetic field. This rule is commonly used in physics and electrical engineering to understand the relationship between magnetic fields and current flow in conductors.

The minimum intensity of white light required for critical inspections using visible magnetic particle inspection methods is 1000 lux/cm² @ 38cm (15").

A centrifuge tube is a type of container that is commonly used in laboratory settings to separate and concentrate substances through the process of centrifugation. While it is not typically used to measure the concentration of a bath in the wet method, it is possible that in certain circumstances, a centrifuge tube may be used for this purpose. However, it is important to note that other containers such as beakers, graduated cylinders, and test tubes are more commonly used for measuring the concentration of solutions in the wet method.

The correct answer is "Lifting test. The DC yoke must lift at least 18 kg (40 lbs)." This means that the performance of a DC yoke is measured by its ability to lift a weight of at least 18 kg or 40 lbs. This test ensures that the DC yoke is strong enough and capable of handling heavy loads.

When an electric current flows through a copper wire, it creates a magnetic field around the wire. This is due to the interaction between the moving charges (electrons) in the wire and the magnetic field they produce. This phenomenon is known as electromagnetism and is the basis for many electrical devices such as motors and transformers. The magnetic field created by the current can be detected using a compass needle or by placing a small magnetic material near the wire.

Passing current through prods can produce circular magnetism. When an electric current flows through a conductor, it creates a magnetic field around it. By passing current through prods, which are typically cylindrical conductors, a circular magnetic field can be generated. This circular magnetism can be useful in various applications such as electromagnets or magnetic stirrers.

The magnetic field generated by a current-carrying wire is directly proportional to the current and inversely proportional to the distance from the wire. In this case, the current passing through both the one-inch and two-inch diameter bars is the same. Since the distance from the wire is also the same for both bars (assuming they are of the same length), the magnetic fields generated by them will be the same.

The correct answer is a mixture of shapes and sizes. In general flaw detection, dry powder magnetic particles are used. These particles are typically a mixture of various shapes and sizes. This mixture allows for better coverage and detection of flaws in the material being tested. By having different sizes and shapes, the particles can adhere to different types of defects and provide a more accurate indication of any flaws present.

The correct answer is 0.1 ml to 0.4 ml per 100 ml of vehicle. This concentration range is considered acceptable for wet fluorescent magnetic particle inspection. It ensures that there is a sufficient concentration of particles in the vehicle to effectively detect any defects or cracks in the material being inspected. Concentrations below this range may result in inadequate particle coverage and reduced sensitivity, while concentrations above this range may lead to excessive background fluorescence and decreased contrast, making it more difficult to identify defects.

When clumping of the particles occurs during the settling test, it indicates that there may be magnetic forces at play. Demagnetizing the suspension in the tube helps to eliminate these magnetic forces, allowing the particles to settle properly. This ensures accurate and reliable results in the settling test.

The minimum intensity of black light required for magnetic particle inspections using fluorescent particles is 1000 W/cm? at a distance of 38cm (15").