1. Calculate the Least Count (LC)
- Main Scale Division (MSD) = $1\text{ mm}$
- Number of divisions on Vernier scale = $10$
- Assuming $10$ Vernier Scale Divisions (VSD) equal $9$ MSD:
- $1 \text{ VSD} = \frac{9}{10} \times \text{MSD} = \frac{9}{10} \times 1\text{ mm} = 0.9\text{ mm}$
- Least Count (LC) = $1 \text{ MSD} - 1 \text{ VSD} = 1\text{ mm} - 0.9\text{ mm} = 0.1\text{ mm}$
- Convert LC to cm: $LC = 0.01\text{ cm}$
2. Determine the Zero Error (ZE)
- The Vernier scale shifts to the left of the main scale zero, indicating a negative zero error.
- The $4^{\text{th}}$ Vernier division coincides with a main scale division.
- Zero Error ($ZE$) = $- (\text{Coinciding VSD} \times LC)$
- $ZE = -(4 \times 0.1\text{ mm}) = -0.4\text{ mm}$
- Convert ZE to cm: $ZE = -0.04\text{ cm}$
3. Calculate the Actual Length
- Observed Reading = $1\text{ cm}$
- Actual Length = Observed Reading - Zero Error
- Actual Length = $1\text{ cm} - (-0.04\text{ cm})$
- Actual Length = $1\text{ cm} + 0.04\text{ cm}$
- Actual Length = $1.04\text{ cm}$
Similar Questions
In a metre bridge experiment, the positions of the cell, E, and galvanometer, G, are interchanged. We shall observe in the galvanometer :
- Savitha, a XI standard student, while conducting an experiment to determine the effective length of a simple pendulum L, notes down the data of time taken to complete 30 oscillations as $60 \text{ s}$ and hence calculates the length of the simple pendulum as :
(Take $\pi^2 = 9.8$, and $g = 9.8 \text{ m/s}^2$) - In a vernier callipers, 20 VSD coincide with 16 MSD (each division of length $1 \text{ mm}$). The least count of the vernier callipers is :
- Which of the following measurements require "index correction" ?
Important Questions from Practical Physics
- For the determination of refractive index of glass slab, a travelling microscope is used whose main scale contains 300 equal divisions equals to 15 cm. The vernier scale attached to the microscope has 25 divisions equals to 24 divisions of main scale. The least count (LC) of the travelling microscope is (in cm) :
In a metre bridge experiment, the positions of the cell, E, and galvanometer, G, are interchanged. We shall observe in the galvanometer :
- Savitha, a XI standard student, while conducting an experiment to determine the effective length of a simple pendulum L, notes down the data of time taken to complete 30 oscillations as $60 \text{ s}$ and hence calculates the length of the simple pendulum as :
(Take $\pi^2 = 9.8$, and $g = 9.8 \text{ m/s}^2$) - In a vernier callipers, 20 VSD coincide with 16 MSD (each division of length $1 \text{ mm}$). The least count of the vernier callipers is :
- Which of the following measurements require "index correction" ?
