Answer.4. All of the above

Explanation

Measurement of Angles

The various methods used for measuring angles and tapers are as follows:

1. Angle gauges
2. Clinometer
3. Bevel protractor
4. Vernier bevel protractor
5. Sine bar
6. Sine centers
7. Taper plug and ring gauges
8. Precision balls and rollers

Answer.1. Statement 1 is true but statement 2 is false

Explanation:-

The angle is defined as the opening between two lines that meet at a point.

Angle Gauge:- Angle gauge blocks are commonly used for measuring the angle in the die insert. Angle gauge blocks are used to set up an angle to the nearest accuracy of3 minutes.

Sin Bar:- A sine bar is used to measure angles precisely with an accuracy of 5′ (five minutes). In this respect, it is more accurate than a bevel protractor and can be used for measuring angles within very closed limits.

For measuring angles, angle gauges are more accurate than the sine bar. They are enabled to measure any angle between 0 degrees and 360 degrees with an accuracy of 0.5 to 0.25 seconds.

The angle gauge blocks are available in sets. A set consists of thirteen separate angle gauge blocks in conjunction with one square block and one parallel straight edge. These are available in the following three series.

First Series (Degree): 1°, 30°, 9°, 27° and 41°

Second Series (Minutes): 1′, 3′, 9′ and 27′

Third Series (Seconds): 3″, 6″, 18″ and 30″

The angle available with the above series can be added or subtracted in order to get a large number of possible combinations. All the pieces of angle blocks are marked with V to indicate the direction of the included angle. Different angles can be obtained by placing the gauge blocks.

Answer.2. 27’- 9’- 3’+1’

Explanation:-

Since we have to find the minutes using an angle gauge. The series used for a minute in angle gauge is 1′, 3′, 9′, and 27′.

The angle available can be added or subtracted in order to get a large number of possible combinations.

Minutes = 27’ − 9’ − 3’ + 1’ = 16’

Answer.4. 75 mm, 15 mm

Explanation:-

The angle gauges are hardened steel blocks of 75 mm in length and 16 mm wide which has lapped surfaces lying at a very precise angle. This set provides angles up to 360° with an interval of 1.5°. They can be wrung together to form either additive or subtractive combinations.

Answer.2. Statement 2 is true but statement 1 is false

The angle gauge blocks are available in sets. A set consists of thirteen separate angle gauge blocks in conjunction with one square block and one parallel straight edge. These are available in the following three series.

First Series (Degree): 1°, 30°, 9°, 27° and 41° = Direct measurement = 1°+ 30° + 9° + 27° + 41° = 81°

Second Series (Minutes): 1′, 3′, 9′ and 27′ =  Direct Measurement = 40′

Third Series (Seconds): 3″, 6″, 18″ and 30″ = 57″

Hence any angle up to 81°, 40′  57’’ be made by a direct combination of angle gauges. Therefore statement 1 iw wrong

For statement 2:-

Interferometry is a measurement method using the phenomenon of interference of waves such as light.

By this interferometry technique, the accuracy and precision of 0.1 s of arc in angular measurement are possible. The gauge length interferometer is normally utilized for such calibration purposes and the angle gauge-under test is carefully wrung onto the platen.

On view through the instrument’s eyepiece, interference patterns are seen consisting of straight, parallel, and equally-spaced interference fringes. However, due to the angle between the surfaces, the pitch of the two sets of fringes will be different, so with suitable calculations, this difference can be found, thereby allowing the necessary calibration to be accurately and precisely achieved.

Answer.1. Both statements -1 and statement – 2 are true and statement – 2 is the correct explanation of statement – 1

Explanation:-

The uses of angle gauges are following:

(i) The angle gauge is used for the quick measurement of angles between two surfaces in engineering industries.

(ii) A frequent use of angle gauges is to check whether the component is within its off-angle tolerance.

(iii) For the measurement of angle more than 90°, by using precision square along with angle gauges.

(iv) Angle gauges are more accurate than sine bars because sine bars involved trigonometric formulas.

(v) Procedure of setting angle with angle gauges is less complex than the setting of angle with sine bar.

Answer.1. Master and tool room

Explanation:-

Angle gauge blocks are available in different accuracy grades, which are chosen in accordance with the intended application.  A prominent U.S. producer of angle gauge blocks uses two accuracy classifications:

Tool Room Angle Gauge:- They are less accurate than master angle gauges. They are less expensive and have an accuracy of ± 1 second.

Inspection Gauges:-  Inspection gauges are those used by inspectors in the final acceptance of the product. They are to ensure that the product is made in accordance with the tolerance specifications on the working blueprints. The inspection gauge has an accuracy of ± 1/2 seconds.

Master gauges:- In addition to the above two, the third type of gauge, known as a master gauge, is sometimes used. Such a gauge is merely a reference gauge with which inspection gauges are periodically compared. The equipment used consists of such tools as precision-gauge blocks, measuring machines, optical flats, microscopes, and projecting equipment. They also referred to as laboratory standards. They are most expensive and have an accuracy of ± 1/4 second.

Answer.4. All of the above

Explanation:-

The applications of angle gauge blocks are multiple, although by far not comparable to that of the regular blocks that are used as length standards. A few examples of angle gage block applications is:

(i) Checking the circular dividing accuracy of rotary tables and dividing heads; this application is comparable to that of the polygon block.

(ii) Setting a revolving work holding table or a magnetic chuck into the required tilt position.

(iii) Inspecting and refining the setting accuracy of tilt tables with graduated segments;

(iv) Providing a reference angle, or a compensating angle, for inspecting angular features on workpieces, whose configuration makes them adaptable for insection with the aid of angle gauge blocks.

Answer.4. All of the above

Explanation:-

Common materials of construction for angle gauges include aluminum, brass or bronze, cast metal or iron, plastic, fiberglass, glass, granite, stainless steel, steel, and wood. These are hardened and stabilized.

Answer.3. Dr. Tomlinson

Explanation:-

Angular gauge was originally developed by N.P.L. by Tomlinson in 1939 and patented in 1941.