Caliper Assessment Vernier Measurement 2 — Questions and Answers
Question 1: A vernier caliper has a main scale reading of 23 mm and the 6th vernier division aligns with a main scale line. If the vernier has 25 divisions equal to 24 mm, what is the measurement?
- 23.24 mm (Correct answer)
- 23.06 mm
- 23.60 mm
- 23.46 mm
Correct answer: 23.24 mm
The least count is 1/25 mm = 0.04 mm, so 6 × 0.04 = 0.24 mm, giving 23 + 0.24 = 23.24 mm.
Question 2: Which part of a vernier caliper is used specifically to measure the internal diameter of a hollow object?
- Upper jaws (Correct answer)
- Lower jaws
- Depth rod
- Locking screw
Correct answer: Upper jaws
The upper (inside) jaws are designed to measure internal dimensions such as bore diameters.
Question 3: A metric vernier caliper reads 47.35 mm. When converted to inches (1 inch = 25.4 mm), what is the nearest correct reading?
- 1.864 in (Correct answer)
- 1.800 in
- 1.921 in
- 1.756 in
Correct answer: 1.864 in
47.35 ÷ 25.4 ≈ 1.864 inches.
Question 4: What does 'parallax error' mean in the context of reading a vernier caliper?
- Error from reading the scale at an angle rather than straight on (Correct answer)
- Error from not zeroing the caliper before use
- Error caused by worn jaws
- Error from measuring a moving object
Correct answer: Error from reading the scale at an angle rather than straight on
Parallax error occurs when the observer's line of sight is not perpendicular to the scale, causing an apparent shift in the reading.
Question 5: On a 50-division vernier caliper (50 vernier divisions = 49 mm), what is the least count?
- 0.02 mm (Correct answer)
- 0.05 mm
- 0.01 mm
- 0.04 mm
Correct answer: 0.02 mm
Least count = 1 mm − (49/50) mm = 1 − 0.98 = 0.02 mm.
Question 6: When measuring a cylindrical rod's outside diameter with a vernier caliper, the rod should be placed:
- Perpendicular to the jaws, fully seated at their base (Correct answer)
- At a 45° angle to increase contact area
- Near the tip of the jaws only
- Against the depth rod
Correct answer: Perpendicular to the jaws, fully seated at their base
Placing the rod fully and perpendicularly seated at the jaw base ensures accurate, repeatable diameter measurement.
Question 7: A vernier caliper's depth rod reads 8 mm on the main scale, and the 4th vernier line coincides on a 10-division vernier. What is the depth?
- 8.4 mm
- 8.04 mm
- 8.40 mm (Correct answer)
- 4.80 mm
Correct answer: 8.40 mm
Least count = 1/10 = 0.1 mm; depth = 8 + (4 × 0.1) = 8.4 mm (written as 8.40 mm to show precision).
Caliper Assessment Vernier Measurement 2
A vernier caliper has a main scale reading of 23 mm and the 6th vernier division aligns with a main scale line.
If the vernier has 25 divisions equal to 24 mm, what is the measurement?