Screw Gauge — NEET Physics MCQs with Solutions
Free NEET Physics Screw Gauge MCQs with step-by-step solutions (36 questions). Part of Units and Dimensions. Practise online on Prepizo — no login needed.
▶ Practise Screw Gauge online (free)
Questions with solutions
Q1 — Screw Gauge · medium · theory
The least count of a screw gauge is
A. Pitch × divisions
B. Pitch ÷ number of divisions on the circular scale ✓ Correct
C. Number of divisions ÷ pitch
D. 1 main scale division
Solution: LC = pitch / (total circular scale divisions).
Q2 — Screw Gauge · easy · theory
The pitch of a screw gauge is
A. The least count
B. The number of divisions on the circular scale
C. The distance moved along the main scale in one complete rotation of the screw ✓ Correct
D. The zero error
Solution: Pitch = linear distance advanced per full rotation of the thimble.
Q3 — Screw Gauge · medium · numerical
A screw gauge has pitch 1 mm and 100 divisions on the circular scale. Its least count is
A. 1 mm
B. 0.01 mm ✓ Correct
C. 0.1 mm
D. 0.001 mm
Solution: LC = 1 mm / 100 = 0.01 mm.
Q4 — Screw Gauge · medium · theory
A screw gauge advances 1 mm in 2 rotations and has 50 circular divisions. Its pitch and least count are
A. Pitch 0.5 mm, LC 0.5 mm
B. Pitch 0.5 mm, LC 0.01 mm ✓ Correct
C. Pitch 2 mm, LC 0.04 mm
D. Pitch 1 mm, LC 0.02 mm
Solution: Pitch = 1 mm / 2 = 0.5 mm; LC = 0.5 / 50 = 0.01 mm.
Q5 — Screw Gauge · easy · theory
The reading of a screw gauge is
A. Circular scale reading only
B. Pitch × divisions
C. Main scale reading + (circular scale division × least count) ✓ Correct
D. Main scale reading only
Solution: Total = MSR + (circular division reading) × LC.
Q6 — Screw Gauge · easy · numerical
A screw gauge (LC = 0.01 mm) reads MSR = 3 mm and circular scale reads 45 divisions. The measured thickness is
A. 3.4 mm
B. 3.45 mm ✓ Correct
C. 4.5 mm
D. 3.045 mm
Solution: 3 + 45×0.01 = 3 + 0.45 = 3.45 mm.
Q7 — Screw Gauge · easy · numerical
A screw gauge (LC = 0.01 mm) reads MSR = 2 mm and circular scale 30 divisions. The reading is
A. 2.03 mm
B. 5.00 mm
C. 2.30 mm ✓ Correct
D. 3.00 mm
Solution: 2 + 30×0.01 = 2.30 mm.
Q8 — Screw Gauge · medium · theory
A screw gauge shows a POSITIVE zero error when, with the studs in contact, the zero of the circular scale is
A. Above the reference line
B. Below the reference (main scale) line ✓ Correct
C. On the reference line
D. Off the scale
Solution: If the circular-scale zero has not reached the reference line (lies below it), the error is positive.
Q9 — Screw Gauge · medium · theory
For a positive zero error, the correct reading of a screw gauge is
A. Observed reading − zero error ✓ Correct
B. Zero error only
C. Observed × zero error
D. Observed reading + zero error
Solution: A positive zero error is subtracted from the observed reading.
Q10 — Screw Gauge · medium · theory
For a negative zero error, the correct reading of a screw gauge is
A. Observed × zero error
B. Observed reading + magnitude of zero error ✓ Correct
C. Ignore the error
D. Observed − zero error
Solution: A negative zero error is added (its magnitude) to the observed reading.
Q11 — Screw Gauge · medium · numerical
With the studs in contact, the 4th circular division is above the reference line (LC = 0.01 mm). The zero error is
A. −0.4 mm
B. 0
C. −0.04 mm (negative) ✓ Correct
D. +0.04 mm
Solution: When the zero has passed the line (circular reads 4 above), the error is negative: −4×0.01 = −0.04 mm.
Q12 — Screw Gauge · easy · theory
The screw gauge works on the principle of a
A. Vernier scale
B. Pendulum
C. Screw and nut (a fine thread converting rotation to linear motion) ✓ Correct
D. Lever
Solution: A calibrated screw thread turns rotation into a small precise linear advance.
Q13 — Screw Gauge · medium · theory
A screw gauge is more precise than a vernier calliper because its least count is typically
A. Larger
B. Zero
C. Smaller (0.01 mm vs 0.1 mm) ✓ Correct
D. The same
Solution: A screw gauge resolves 0.01 mm, ten times finer than a typical vernier's 0.1 mm.
Q14 — Screw Gauge · medium · theory
A screw gauge is best suited to measure
A. The depth of a well
B. A large rod's length
C. The length of a room
D. The diameter of a thin wire ✓ Correct
Solution: Its very small least count makes it ideal for tiny thicknesses like wires and sheets.
Q15 — Screw Gauge · easy · theory
The "backlash error" in a screw gauge is avoided by
A. Rotating back and forth
B. Using zero error
C. Ignoring the circular scale
D. Always rotating the screw in the same direction while taking a reading ✓ Correct
Solution: Turning consistently in one direction avoids the slack (backlash) between screw and nut.
Q16 — Screw Gauge · medium · numerical
A screw gauge (LC = 0.01 mm) has a positive zero error of +0.03 mm and an observed reading of 1.52 mm. The corrected reading is
A. 1.52 mm
B. 1.55 mm
C. 1.49 mm ✓ Correct
D. 1.03 mm
Solution: Correct = observed − zero error = 1.52 − 0.03 = 1.49 mm.
Q17 — Screw Gauge · medium · numerical
A screw gauge (LC = 0.01 mm) has a negative zero error of −0.02 mm and an observed reading of 2.40 mm. The corrected reading is
A. 2.38 mm
B. 2.02 mm
C. 2.40 mm
D. 2.42 mm ✓ Correct
Solution: Correct = observed − (−0.02) = 2.40 + 0.02 = 2.42 mm.
Q18 — Screw Gauge · easy · theory
The ratchet in a screw gauge is used to
A. Apply a consistent, gentle pressure and avoid over-tightening ✓ Correct
B. Cause zero error
C. Read the main scale
D. Increase the least count
Solution: The ratchet slips at a fixed torque, ensuring uniform pressure on the object.
Q19 — Screw Gauge · medium · numerical
A screw gauge with pitch 0.5 mm and 100 circular divisions has a least count of
A. 0.05 mm
B. 0.5 mm
C. 0.005 mm ✓ Correct
D. 0.01 mm
Solution: LC = 0.5 mm / 100 = 0.005 mm.
Q20 — Screw Gauge · easy · theory
The circular (head) scale of a screw gauge is on the
A. Fixed main scale
B. Frame
C. Anvil
D. Rotating thimble ✓ Correct
Solution: The circular scale is engraved on the rotating thimble.
Q21 — Screw Gauge · easy · theory
If the circular scale completes one full turn, the reading advances by the
A. Pitch ✓ Correct
B. Zero error
C. Least count
D. Diameter
Solution: One full rotation moves the spindle forward by exactly one pitch.
Q22 — Screw Gauge · medium · numerical
A screw gauge reads MSR = 5 mm, circular scale 0 divisions (LC = 0.01 mm), with no zero error. The reading is
A. 50 mm
B. 0.05 mm
C. 5.50 mm
D. 5.00 mm ✓ Correct
Solution: 5 + 0×0.01 = 5.00 mm.
Q23 — Screw Gauge · easy · theory
The main scale of a screw gauge is usually graduated in
A. inches
B. micrometres
C. centimetres
D. half-millimetres or millimetres ✓ Correct
Solution: The linear main scale is marked in mm (often with half-mm divisions).
Q24 — Screw Gauge · easy · numerical
The precision of a screw gauge is generally
A. 0.01 mm ✓ Correct
B. 0.1 mm
C. 1 cm
D. 1 mm
Solution: A standard micrometer screw gauge resolves 0.01 mm.
Q25 — Screw Gauge · medium · theory
The zero error of a screw gauge is a
A. Gross error
B. Systematic error corrected in every reading ✓ Correct
C. Random error
D. Least count
Solution: It is a constant, directional (systematic) error that must be corrected each time.
Q26 — Screw Gauge · easy · numerical
A screw gauge (LC 0.01 mm) reads MSR = 4 mm and circular scale 82 divisions. The measured value is
A. 8.2 mm
B. 4.8 mm
C. 4.82 mm ✓ Correct
D. 4.082 mm
Solution: 4 + 82×0.01 = 4.82 mm.
Q27 — Screw Gauge · easy · theory
A screw gauge is also commonly called a
A. Barometer
B. Spherometer
C. Micrometer ✓ Correct
D. Vernier
Solution: The micrometer screw gauge is often just called a micrometer.
Q28 — Screw Gauge · medium · theory
Increasing the number of divisions on the circular scale (same pitch)
A. Decreases the least count (more precision) ✓ Correct
B. Increases the pitch
C. Increases the least count
D. Has no effect
Solution: LC = pitch / divisions, so more divisions gives a smaller least count.
Q29 — Screw Gauge · easy · theory
A spherometer, unlike a screw gauge, is chiefly used to measure
A. A wire's diameter
B. The radius of curvature of a spherical surface ✓ Correct
C. External diameters
D. Depth of a beaker
Solution: A spherometer (also based on a screw) measures curvature/thickness of curved surfaces.
Q30 — Screw Gauge · medium · numerical
A screw gauge with pitch 1 mm and 200 circular divisions has least count
A. 0.02 mm
B. 0.005 mm ✓ Correct
C. 0.01 mm
D. 0.5 mm
Solution: LC = 1 mm / 200 = 0.005 mm.