This set of Engineering Metrology Multiple Choice Questions & Answers (MCQs) focuses on “Working Mechanism of Dial Indicators”.
1. Which of the following is necessary for the working mechanism of dial indicators?
a) High magnification ratio
b) Low magnification ratio
c) Moderate magnification ratio
d) Good magnification ratio is achieved by using gear and pinions in a large area
Explanation: High magnification ratio is important in this instrument which is achieved by the use of an arrangement of gears and pinions in a small area. Gear train is arranged in a manner similar to a clock movement.
2. What is the purpose of a pin which is located in a slot in rack guide in dial indicator?
a) Prevent movement of plunger perpendicular to its own axis
b) Prevent rotation of plunger about its own axis
c) Prevent plunger displacement
d) Prevent movement of plunger in case of misalignment
Explanation: The plunger rotation about its own axis is prevented by a pin which is located in a slot in a rack guide carries a rack accurately meshing with the pinion. The plunger is a perfect sliding fit in its bearings.
3. What is the pressure exerted by spring in dial gauge?
a) 2 oz
b) 3 oz
c) 4 oz
d) 6 oz
Explanation: In order to keep the plunger in a normal position or extended position a spring is used. This spring is a light coil spring and the pressure exerted by this spring is of about 6 oz.
4. Why rotatable bevels are used in dial indicators?
a) Facilitate the work of machine setting
b) Acts as an offset attachment
c) Prevent shocks
d) For making final zero setting
Explanation: Most of the dial indicators include a rotatable bezel. Rotatable bezel is used to make the final zero setting at any position in the full circle. A clamp is also provided for locking it in any position.
5. Which of the following is attached to dial face for rapid checking of parts?
a) Tolerance pointers
b) Contact points
c) Special stems
d) Lever attachments
Explanation: Tolerance pointers can be attached to the dial face for rapid checking of the parts. These pointers can be used to clearly indicate any tolerance, whether bilateral or unilateral, on the dial gauge.
6. What is the purpose of lever attachment used in dial indicators?
a) Checking of parts
b) Transfer motion at the right angle to the spindle
c) Transfer motion at the 180 degree to the spindle
d) Transfer motion at the 60 degree to the spindle
Explanation: Lever attachments are very useful part in a dial indicator. The attachment transfers motion 90 degree directly to the indicator spindle. There is provision to avoid any type of errors caused due to play in bearings and wear.
7. Which of the following is used to inspect deep recesses by dial indicators?
a) Rotatable bezels
b) Cushioned pointers
c) Stem indicators
d) Contact points
Explanation: Dial indicators can also be used inspect deep recesses but in this case, an additional part attachment is required i.e. a stem indicator. Long stem indicators are used where deep recesses are to be inspected.
8. Which of the following option is true for given statements about dial indicators?
Statement 1: Gears are precision cut to prevent backlash.
Statement 2: Change of contact points make dial indicators more versatile.
a) T, F
b) F, F
c) F, T
d) T, T
Explanation: To take up the backlash, a hair spring is fitted to the dial gauge gear trains by a gear and pinion meshing. The gears are precision cut and the movement assembly resembles that of high-grade watch to prevent the gear from backlash.
9. Why a revolution counter is used in dial gauge?
a) To withstand sudden shock
b) To indicate correctly the number of revolution
c) To count and display the number of revolutions
d) To transfer motion at right angle
Explanation: A revolution counter is present in dial gauge, if the pointer makes more than one revolution, it will correctly indicate the number of revolutions and enable a complete reading to be made when the indicator is used for direct measurement.
Sanfoundry Global Education & Learning Series – Engineering Metrology.
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