Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET
Exam
NEET
Subject
Physics
Chapter
Experimental Physics

NEET · Physics · Experimental Physics

A specialized Vernier calliper has its main scale graduated such...

A specialized Vernier calliper has its main scale graduated such that 11 main scale division is equal to 0.50.5 mm. Twenty Vernier scale divisions are equal to nineteen main scale divisions. When the jaws are fully closed, the zero of the Vernier scale is to the right of the zero of the main scale, and the 5th5^{\text{th}} Vernier division coincides with a main scale division. While measuring the diameter of a cylinder, the main scale reading is 1.51.5 cm and the 12th12^{\text{th}} Vernier division coincides with a main scale division. The corrected diameter of the cylinder is :

Options

  1. A1.54251.5425 cm
  2. B1.51751.5175 cm
  3. C1.53001.5300 cm
  4. D1.62001.6200 cm

Correct answer

B. 1.51751.5175 cm

Step-by-step solution

The least count (LC) of the Vernier calliper is calculated as:

1 MSD=0.5 mm1 \text{ MSD} = 0.5 \text{ mm}

20 VSD=19 MSD⇒1 VSD=1920×0.5 mm=0.475 mm20 \text{ VSD} = 19 \text{ MSD} \Rightarrow 1 \text{ VSD} = \dfrac{19}{20} \times 0.5 \text{ mm} = 0.475 \text{ mm}

LC=1 MSD−1 VSD=0.5 mm−0.475 mm=0.025 mm=0.0025 cm\text{LC} = 1 \text{ MSD} - 1 \text{ VSD} = 0.5 \text{ mm} - 0.475 \text{ mm} = 0.025 \text{ mm} = 0.0025 \text{ cm}

When the jaws are closed, the Vernier zero is to the right of the main scale zero, indicating a positive zero error.

Zero error=+5×LC=+5×0.0025 cm=+0.0125 cm\text{Zero error} = +5 \times \text{LC} = +5 \times 0.0025 \text{ cm} = +0.0125 \text{ cm}

During the measurement, the observed reading is:

Observed reading=Main scale reading+(Vernier scale reading×LC)\text{Observed reading} = \text{Main scale reading} + (\text{Vernier scale reading} \times \text{LC})

Observed reading=1.5 cm+(12×0.0025 cm)=1.5 cm+0.0300 cm=1.5300 cm\text{Observed reading} = 1.5 \text{ cm} + (12 \times 0.0025 \text{ cm}) = 1.5 \text{ cm} + 0.0300 \text{ cm} = 1.5300 \text{ cm}

The corrected diameter is obtained by subtracting the zero error from the observed reading:

Corrected reading=Observed reading−Zero error\text{Corrected reading} = \text{Observed reading} - \text{Zero error}

Corrected reading=1.5300 cm−0.0125 cm=1.5175 cm\text{Corrected reading} = 1.5300 \text{ cm} - 0.0125 \text{ cm} = 1.5175 \text{ cm}

Answer: 1.51751.5175 cm
Practice Experimental Physics on Quantrex Academy →

More from Experimental Physics

One main scale division of a Vernier calliper is equal to 1 mm and the number of… NEET 2026In a vernier callipers, 20 VSD coincide with 16 MSD (each division of length 1 mm). The… NEET 2026Which of the following measurements require ‘index correction’ ? NEET 2026Consider the diameter of a spherical object being measured with the help of a Vernier… NEET 2025The pitch of an error free screw gauge is 1 mm and there are 100 divisions on the… NEET 2024In a vernier callipers, (N+1) divisions of vernier scale coincide with N divisions of… NEET 2024A screw gauge gives the following readings when used to measure the diameter of a wire… NEET 2021The angle of 1 ' (minute of arc) in radian is nearly equal to NEET 2020 Full Experimental Physics list All NEET PYQs