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Correct choice is (a) 5

The explanation: The shore scleroscope number is obtained by conducting the EXPERIMENT 5 times and taking an average of the obtained 5 values. The FINAL obtained average VALUE is considered shore scleroscope number.

Right ANSWER is (b) 5 inch per inch gage length

To EXPLAIN: The FORMULA of normal ELONGATION is given by = \(\frac{Expected \, yield\, strength}{Modulus \,of\, ELASTICITY}\)

= \(\frac{50,000}{10,000}\)

= 5 inches per inch gage length.

Right choice is (c) 1 INCH

For explanation I WOULD say: Specimen of fatigue TESTS are typically rolled or forged bar stock. The are ONE inch in diameter. They can vary depending on the REQUIREMENTS and the material being tested to determine fatigue strength.

The CORRECT choice is (b) False

To explain: It is not very effortless or easy to OBTAIN the exact desired radius of bending in the bending test being performed. But this test can OFTEN be used in shops etc. to check the PROPERTIES of the material if there is a doubt about them.

The CORRECT option is (c) 18 inches

Easy EXPLANATION: There are TWO methods of demagnetization. One of the methods involves withdrawing the specimen to a distance of eighteen inches away from the coil. This is to avail the EFFECT of the weak current.

Correct answer is (d) time-consuming

Explanation: There are a lot of ADVANTAGES and DISADVANTAGES of standard inspection METHODS. When it COMES to radiography, one of the disadvantages is that it can be time-consuming. It also needs PHOTOGRAPHY.

Right ANSWER is (a) normal

Explanation: The material or the specimen should be positioned in true axial alignment. This is considered vital, ESPECIALLY since materials used in aircraft construction are thin. This will avoid DAMAGING them.

Right choice is (c) 1/16

To elaborate: The crosshead of the tension TESTING MACHINE has a certain advisable LIMIT in speed it has to be operated up to. It is different until the yield point and after yield point TILL RUPTURE. Until yield point it is 1/16 inch, yield point to rupture it is 1/2 inch. (Inch per inch)

The correct answer is (a) 0.0003

Best explanation: For a LENGTH of one inch, the PERMANENT SET of over 0.0001 inch withstanding is proof stress. For 3 INCHES length, it will be –

0.0001×3 = 0.0003 inches.

Hence, it is 0.0003 inches.

The correct answer is (a) True

The best EXPLANATION: Tension TESTING can give us crucial information REGARDING the properties of a material. Apart from the ultimate tensile strength, the yield strength and reduction in AREA can be DETERMINED through tension testing.

The CORRECT ANSWER is (a) no necessity to plot a curve

Explanation: The extension under load method is USED much more than the set method. This is due to the fact that the former method does not require the plotting of a curve to find the yield STRENGTH of a material.

The CORRECT choice is (a) 3

The best EXPLANATION: In a flattening test, the maximum limit up to which the THICKNESS of the tube can be considered is THREE TIMES the thickness of the wall. This is in the case of bronze tubing in flattening test.

Correct option is (B) False

The explanation is: The STATEMENT is not true as the IMPACT test does not determine the shock resistance of the particular material. The impact test can indicate if the material is extremely BRITTLE. It also tells US if a material has undergone the right heat treatment or not.

Right answer is (a) 30kg

To EXPLAIN: In the Vickers/diamond hardness test, the AMOUNT of LOAD applied typically on homogenous material is 30kg. 5kg is the weight applied to materials that are soft or those that have a hard SURFACE.

Right option is (a) Rotating-beam TESTS

Easy explanation: There are several different types of fatigue testing apparatus AVAILABLE to test MATERIALS or specimen. But the most widely USED apparatus is rotating-beam tests also called as rotating-cantilever tests.

The correct option is (b) False

Best explanation: This statement is INCORRECT. X-rays are not stronger COMPARED to gamma-rays. In fact, the CONTRARY is true. X-rays are weak compared to gamma-rays, due to which gamma-rays can be used to inspect materials of greater thickness.

The correct answer is (a) ELASTIC limit

To ELABORATE: The proof stress of a MATERIAL can be found or determined the same way the elastic limit can be determined. But, there are other methods through which the elastic limit can be found as well.

The CORRECT choice is (c) 0.0001

For explanation: The highest possible stress a material can, WITHOUT causing a permanent SET of more than 0.00001 inch per inch of the gage length is called PROOF stress. This is after the total release of the stress.

Correct choice is (C) tubing

Easy explanation: Flattening test is typically APPLICABLE for tubing. ROUND steel wire generally undergoes reverse bend test. Both of these are methods used to find the nature of the material, more SPECIFICALLY the ductility.

Correct CHOICE is (d) Notches and HOLES

The best I can explain: It is NECESSARY that the specimen being tested to determine fatigue strength not have notches and holes in it. The specimen is usually cylindrical rods that do not CONTAIN any of the above defects.

Correct CHOICE is (d) 3/16

The best I can explain: If the diameter of the wire in which the test is being carried out is less than 3/16 inches of diameter, the JAWS of the VICE are rounded to 3/16 inches. For wires of GREATER weight, the vice is SET to 3 times the diameter of the wire.

The CORRECT answer is (d) mild carbon steel

Easiest explanation: The YIELD point is not present in all available materials. It is present in certain materials like Mild carbon steel and wrought IRON. It does not EXIST in wood, pure carbon or pure molybdenum. There are two methods to determine the yield point of a material.

The correct answer is (a) smooth

Easiest explanation: The materials that have a SHARP break in the yield point of the stress-strain curve tend to have a yield point. These are materials LIKE WROUGHT IRON. Other materials have a smooth REGION in the place of the sharp break of yield point, hence do not have this property.

The correct OPTION is (d) DROPPING

The BEST I can explain: This hardness test is carried out by comparing the rebound ALTITUDE of the test material after dropping a TINY diamond pointed hammer on the test specimen, to that of a standard test material.

Right option is (B) 500

Easy explanation: Different amount of load are applied on test specimen depending UPON the TYPE of MATERIAL being tested. For steel testing, the pressure applied is 3000kg. For comparatively softer MATERIALS like aluminium alloys, the pressure applied is 500kg.

The correct OPTION is (b) 7 BENDING’s

Easiest explanation: For heavy wire, the RATE of bending in the reverse bend test is 7 bends per MINUTE. For SMALL wire, the rate of bending in the experiment is fifty bends per minute. This is the specification given.

Right option is (b) False

To elaborate: The bending TEST being performed on the test specimen is to GAUGE the ductility of the material. Once the test is performed, if the specimen has passed the test, it means that the material is most LIKELY not going to be destroyed due to fatigue STRESSES.

The correct answer is (B) 2

The explanation: The FLATTENING test is generally APPLIED for tubing. It gives an idea about the ductility of the material. In this test, the LENGTH of the TUBE is taken as two times the diameter. It is flattened in a sideways direction and scrutinized to detect any defects.

The correct choice is (b) To DETERMINE if the material has been subjected to heat treatment

Explanation: The PRINCIPAL or main reason that the impact TEST is conducted upon a material is to ASCERTAIN if the material has undergone the required accurate heat treatment. The experiment gives no absolute value.

Correct option is (c) outer circumference

The best I can explain: If we desire to OBTAIN the complete EXTENT of the bending TEST being performed, it is necessary to compute the BEND of the outer circumference of the test SPECIMEN in the experiment.

Correct ANSWER is (c) 0.425 J per mm square

For explanation I would say: Formula for impact strength = \(\frac{Energy \,absorbed}{Cross-section \,AREA \,of \,NOTCH}\)

= \(\frac{34}{10×8}\)

= 0.425 J per mm square.

Right choice is (d) Color

To explain: MAGNAFLUX is a magnetic inspection METHOD USED to detect defects and non-metallic quantities in a magnetic material. It can detect CRACKS, seams etc. but cannot detect COLOUR of the specimen.

Right answer is (d) 60rpm

To explain I WOULD say: The torsion TEST experimental set up contains TWO clamps. One is rotatable and the other FIXED. The rotatable clamp is moved at a rate of 60rpm (rotations per minute) at maximum. This is because exceeding that speed MIGHT cause heating.

The correct choice is (c) CURRENT is put on throughout the process

To explain: The continuous METHOD of magnaflux involves inducing both CIRCULAR and longitudinal current at the same time and RUNNING it throughout the entire process. This is known to give good RESULTS.

The CORRECT option is (a) True

For explanation: The above STATEMENT is true. Fluoroscopy is a method of non-destructive INSPECTION that has been DEVELOPED after radiography. It REQUIRES a higher voltage compared to radiography to perform.

Correct answer is (d) POINT where there is a substantial increase in elongation WITHOUT a rise in load

The best I can explain: A materials yield point is the point where there is a significant increase in the elongation without an increment in the load. The yield point of a material can be DETERMINED in two WAYS – the divider method, and DROP of beam method.

Right OPTION is (c) +3/2 %

To elaborate: The process of tension testing MUST adhere to certain conditions to ASSURE its validity. ONE of the conditions is the RANGE of accuracy of the testing machine. The percentage within which the accuracy should be present is 3/2%.

The CORRECT choice is (c) 136°

To elaborate: The INCLUDED angle of the square based, pyramid diamond PENETRATOR in the Vickers/diamond HARDNESS TEST is 136°. 15° and 23° would be too low of an angle to be considered.

Correct answer is (a) soft

To explain: There is a relation between hardness and tensile strength for MATERIALS like CARBON and low alloy steels. The tensile strength can be PREDICTED USING hardness values. But for comparatively soft materials like ALUMINIUM alloys, this is not applicable.

Correct answer is (a) Round steel wire

Best EXPLANATION: Round steel wire is USUALLY the most widely used specimen while performing the REVERSE BEND TEST in laboratories. Wood and glue cannot be used or have the bending test performed on them.

The CORRECT option is (a) True

For explanation I would say: The IMPACT test value can change with change in temperature. For EXAMPLE, consider an impact test conducted at a low temperature. The impact test value DECREASES. Hence with a decrease in temperature, the impact energy is reduced.

Right answer is (c) 1

Explanation: The specimen being used in the bending test, if it’s a sheet or strip STOCK TYPICALLY has a width of ONE inch. The general length of the specimen considered is six INCHES. The edges of the specimen should not contain ROUGH spots.

The correct CHOICE is (c) COMPARE TWO specimens of similar composition and TENSILE strength

The EXPLANATION: The impact test can be used to compare two specimens that have a similar composition and tensile strength. It has no absolute value. The test used to determine the tensile strength of a material is the tension test.

The correct ANSWER is (d) 1/16^th

The best EXPLANATION: The specimens of forging stock ALSO undergo the bending TEST. They are machined to a minimum of six inches in length. Their edges are rounded to a one by sixteenth radius. It differs for heavy material.

Right option is (a) THREADED

Explanation: The tensile specimen in the CHARPY impact test is threaded on both SIDES. One of the ends is threaded to the pendulum that is swinging. It is not axed, heated or subjected to any such TREATMENT before being tested.