Pick up the correct statement from the following:
A) It is difficult to eliminate an error completely at first trial
B) Instability of the instrument makes it almost impossible to adjust it satisfactorily
C) Adjustment screws must be left bearing firmly but should never be forced
D) All the above
The correct answer and explanation is :
The correct answer is:
D) All the above
Explanation:
Each of the statements provided is correct and plays a crucial role in understanding the functioning and handling of instruments, particularly in fields such as surveying, engineering, and scientific measurements.
1. It is difficult to eliminate an error completely at first trial
Errors in measurement can be classified into different types, including systematic errors, random errors, and human errors. Even with precise instruments and careful techniques, achieving a perfect measurement on the first attempt is rare. Several iterations, recalibrations, and adjustments are usually required to minimize errors as much as possible.
2. Instability of the instrument makes it almost impossible to adjust it satisfactorily
Instrument stability is a crucial factor in obtaining accurate measurements. External factors such as vibrations, environmental changes (temperature, humidity, pressure), and mechanical wear can cause instability. If an instrument is not stable, repeated adjustments may not hold, making it difficult to obtain consistent and reliable readings.
3. Adjustment screws must be left bearing firmly but should never be forced
Adjustment screws are used to fine-tune instruments for precise alignment and calibration. Applying excessive force can damage the instrument, strip the threads, or cause misalignment. Therefore, they should be tightened firmly but not excessively, ensuring smooth operation without introducing additional errors.
Since all three statements are valid and relevant, the correct answer is D) All the above.
Image Representation:
Below is an image illustrating instrument stability, error correction, and proper handling of adjustment screws.
