1. What is the value of measuring pressure in dial comparator bench micrometer?
a) 7.5 N
b) 8.5 N
c) 9.5 N
d) 10 N
Explanation: Measuring pressure in dial comparator bench micrometer is about 7.5 N. Spindle thread pitch is 1 mm. Throat depth is about 32 mm.
2. Which of the following option is correct about bench micrometer?
Statement 1: Friction free motion transfer between anvil and indicator.
Statement 2: Anvil is retractable by trigger control.
a) Statement 1 is correct
b) Statement 2 is correct
c) Both the statements are correct
d) Both the statements are incorrect
Explanation: There is a mechanism for linear friction free motion transfer between anvil and indicator. This is to achieve high accuracy. Retracting of the anvil is done by trigger control. Work is placed between spindle and anvil after retracting and then released.
3. What is the workrest diameter in bench micrometer with dial comparator?
a) 12 mm
b) 14 mm
c) 16 mm
d) 18 mm
Explanation: Workrest diameter is 14 mm with 12 mm height adjustment. Work rests between spindle and anvil. It can be raised to a selected height by using an adjustable work table.
4. At which interval, the graduated scales are graduated?
a) 1 mm
b) 10 mm
c) 100 mm
d) 10 cm
Explanation: At the intervals of 1 mm, graduated scales are accurately graduated.
5.Which of the following option is correct about given statement?
Statement 1: In conjunction with other instruments, graduated scales can be used for machine setting.
Statement 2: Graduated scales has fixed anvil.
a) T, T
b) F, T
c) T, F
d) F, F
Explanation: With micrometer microscope, graduated scales can be used for instrument and machine set to a high order of accuracy.
6. When glass block is tilted by ‘i’ in optical arrangement with a graduated scale, then find out the displacement of the ray. Given, width=5 mm, refractive index of glass block=1.5 and rotation is 10 mins.
a) 0.05 mm
b) 0.005 mm
c) 0.0005 mm
d) 0.00005 mm
Explanation: For very small angles, h=wi(Ref index-1/Ref index).
7. What is the accuracy range when Graduated scales are used with micrometer microscope?
a) ±1 micron
b) ±1/2 of a micron
c) ±1/4th of a micron
d) ±3/4th of a micron
Explanation: Use of microscope micrometer increases the accuracy of graduated scales. ±1/4th of a micron is the accuracy range when Graduated scales are used with micrometer microscope.
8. Which of the following is incorrect about graduation scales?
a) Scribed or etched marks are less preferable than paints
b) Telescope internal gauge has two spherical contact rods
c) Ball type plug gauge can detect ovality and taper effect
d) Pneumatic hole gauges are used for precision hole gauging
Explanation: Scribed and etched graduations are more preferable than inks. It is for the durability and accuracy of graduations.
9. Which of the option is correct for given statements about graduated scales?
Statement 1: A microscope is fitted over the scale markings for machine setting.
Statement 2: This arrangement has a provision of the micrometer.
a) Only statement 1 is true
b) Only statement 2 is true
c) Both the statements are true
d) Both the statements are not true
Explanation: A microscope is fitted and setting lines are engraved on the microscope eyepiece. This arrangement has a micrometer provision to move the setting lines.
10. In optical arrangement with graduated scale, when glass block is tilted by ‘i’ then incident ray from scale deviates from straight line path. What is the displacement ‘h’? ( w is the glass width)
a) sin(i-r)/wcosr
b) w cos(i-r)/sinr
c) w sin(i-r)/cosr
d) cos(i-r)/wsinr
Explanation: Scale division is sensed in the same position when optical axis and glass block are perpendicular to each other. Then it travels a straight line. But when glass block is tilted then incident ray is refracted by ‘r’.