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The correct option is (a) True

For explanation I WOULD say: The range between the lower tolerance limit and UPPER tolerance limit is always set by a producer to make dimensions to come within the range, but the narrowing or shortening of range makes the casting more expensive and DIFFICULT to PRODUCE, and problems also arise while testing of casting.

Correct choice is (a) Fast-accurates

To ELABORATE: The category of fast-accuratives has the characteristics of spending less time and MAKING few errors, and this is according to the subject CLASSIFICATION of MFFT.

The correct answer is (a) Slow accurates

For explanation: The subjects on taking the MFFT, the subjects were then CLASSIFIED into FOUR CATEGORIES namely, fast-accurates, reflectives, impulsives and slow-inaccurates. Slow-accurates was not one of the classifications.

The CORRECT choice is (c) Magnetic particle inspection

For explanation I would say: Magnetic particle inspection (MPI) is a method of LOCATING SURFACE and subsurface discontinuities in ferromagnetic materials. In this method, the material or part is magnetized and then the magnetic discontinuities occur which indicates the size, shape and EXTENT of discontinuities.

Correct option is (a) True

To EXPLAIN: MECHANICAL testing often involves deformation and breakage of SAMPLES of materials. A machine called UTM (Universal Testing Machine) is conventionally USED, in which specimen is LOADED or fixed at the chuck side and it performs various types of test like tension test, compression test etc.

The CORRECT option is (b) Crack within the CAST

Easiest explanation: Visual inspection can be USED for detection of many kinds of defects like CRACKS, tears, blowholes, rattails, metal PENETRATION, swells, shifts and many more. But for detecting cracks within the cast, visual inspection is not the way.

Right answer is (d) PRESSURE test

Best explanation: Pressure test is BASICALLY a type of non-destructive test in which a GAS is injected in a closed casting, and then the casting is dipped into water and if it produces any leak of gas in the water, that basically shows presence of DEFECTS in the casting that can be simply observed by visual INSPECTION. And the test like a stress test, hardness test and crash test, these are related to the destructive testing of materials.

Right option is (a) True

Easy explanation: In the impact TEST, the casting is SUBJECTED to a BLOW by the help of a hammer of known WEIGHT, which basically strikes or falls on the SURFACE of the casting. Defective castings fail due to the impact of the blow, but this method is very crude and unreliable to the material or casting which is inspected.

The correct answer is (b) False

To explain I WOULD say: The SIMPLEST test specimens are smooth and un-notched, but more complex geometries can be USED to produce conditions resembling those in actual engineering components. Notches like holes, slots or grooves that have defined radius can be MACHINED in specimens. This gives more accurate information about the material.

Right answer is (b) False

For explanation I would say: Dimensional INSPECTION mainly reduces the time and cost of machining when the CASTING is made. This method GIVES accurate details and proper forecasting can be possible before the machining process which GREATLY helps to MAKE the casting more economical and reliable for the application.

Right choice is (b) False

Easy explanation: Visual INSPECTION can be CARRIED out using VARIOUS equipment such as Mark 1 eyeball or Mark 0 eyeball. For CARRYING out visual inspection, detecting defects can be done using the naked eye too.

The correct answer is (d) α = 20 log(A0/A)/X

To explain I WOULD say: Ultrasonic attenuation coefficient (α) is calculated from the following equation-

α = 20 log(A0/A)/X

Where, A0 and A are the ULTRASOUND AMPLITUDES before and after travelling through the material, and X is the travel distance. The measurement of attenuation coefficient is mainly USED to find qualitative and quantitative information on the internal structure of PRODUCTS or castings.

Correct ANSWER is (a) True

For explanation I would say: The ability of rays to penetrate through the metal mainly DEPENDS on the density of metal and they can penetrate more easily where LESS density of metal is present and it LEADS to the formation of shadow picture on the film. And any defects in the CASTING can easily be identified from the shadow picture.

The CORRECT OPTION is (a) True

The explanation: The FATIGUE performance of the material is generally evaluated by ENDURANCE limit of the metal which indicates maximum stress, stress range or stress amplitude. It is also determined by a number of LOAD cycles which are applied to the material or casting for the evaluation of properties.

Right answer is (b) False

Best explanation: In destructive testing, ANALYZING of destructive failure mode is often completed using a high-speed camera, which records continuously until the failure is detected. Detection of the failure can be ACCOMPLISHED by using a sound detector which PRODUCES a SIGNAL to start the high-speed camera.

The CORRECT answer is (a) True

To explain: Eddy current conductivity testing method is commonly used to ASSESS heat damage of various heat treatable alloys. In order to have a quantitative assessment of heat damaged material, the establishment of conductivity, hardness and STRENGTH, a (CHS) relationship is REQUIRED for each alloy.

Correct option is (b) False

The EXPLANATION: In MPI method, after the magnetization of the MATERIAL or PART which to be INSPECTED, the magnetic discontinuities that lie in a direction generally transverse to the direction of the magnetic FIELD. This causes a leakage field to form at and above the surface of the part, which indicates the presence of surface discontinuities.

The correct ANSWER is (b) False

Best explanation: Acoustic emission testing method, in which SOLID materials EMIT sound or acoustic emission when they are stressed MECHANICALLY or thermally to the point where deformation or fracturing occurs. This creates ELASTIC waves which can be analyzed by an acoustic emission test system to monitor the condition of the material or casting under stress.

The CORRECT answer is (d) Pressure test

For explanation I would say: Pressure test used on castings REQUIRED to be leak proof. In this METHOD, all the openings of the casting are closed and then gas with high pressure is introduced in it. If the casting is having a porosity or another defect, then it can be detected by leaking of gas in the WATER when the casting is submerged into the water.

Right choice is (b) False

To elaborate: Destructive testing method can be applicable to the LARGE structures but it is not ECONOMICAL because destruction of large casting or structure will CAUSE steep downing of productivity. So for large structures or castings, other METHODS are used for the inspection like modeling by finite ELEMENT software.

Right OPTION is (c) Shear test

Explanation: In the mechanical PROPERTIES of material, hardness is basically defined as the RESISTANCE of a material to penetration. To characterize hardness, it can be divided into three primary categories such as scratch test, REBOUND test and indentation test. Shear test is not the part of hardness testing; it is used to MEASURE shearing strength of the material.

Correct answer is (b) False

For explanation I WOULD say: To ensure a part meets dimensional requirements, dimensional INSPECTION helps GREATLY, in which a metal casting facility can check the dimensional accuracy of a part manually or by the help of coordinate measuring machine (CMM). And any TOLERANCE can be MAINTAINED easily by dimensional inspection.

The correct option is (a) True

For explanation I WOULD say: During the formation of positive surface irregularity on the casting, an excess amount of METAL has to PENETRATE into the ceramic mold MATERIAL, or there should be an ENTRAPMENT from air to liquid next to the pattern.

Right choice is (d) ULTRASONIC inspection

Easiest EXPLANATION: In the ultrasonic inspection, a beam of high frequency sound waves is introduced into material for the detection of interior flaws in the material. Then the sound wave travels through the material with some loss of energy and are REFLECTED at INTERFACES, which are further ANALYZED to define the presence and location of flaws in the casting.