1. Atmospheric refraction is _________
a) instrumental error
b) natural error
c) personal error
d) it’s not an error
Explanation: Atmospheric refraction is a natural error. Settlement of tripod or turning points, wind vibrations are also natural errors.
2. Which of the following is an instrumental error?
a) earth’s curvature
b) mistake in rod handling
c) mistakes in recording
d) error due to sluggish bubble
Explanation: Earth’s curvature is a natural error. Mistake in rod handling, mistakes in recording are personal errors. Error due to sluggish bubble is an instrumental error.
3. Which of the following is not a natural error?
a) error due to defective joint
b) atmospheric refraction
c) wind vibrations
d) earth’s curvature
Explanation: Atmospheric refraction, wind vibrations, earth’s curvature are natural errors. error due to a defective joint is an instrumental errors.
4. Which of the following is not a principle source of error in levelling?
a) instrumental error
b) natural error
c) personal error
d) Systematic error
Explanation: All levelling measurements are subjected to three principal source of errors. Systematic error is also called cumulative error.
5. Errors in sighting is _________
a) instrumental error
b) natural error
c) personal error
d) Systematic error
Explanation: Errors in sighting is a personal error. Mistakes in manipulation, mistakes in rod handling, mistakes in reading the rod etc also come under personal error.
6. Wind vibrations are natural errors.
a) True
b) False
Explanation: Wind vibrations is a natural error. Atmospheric refraction, settlement of tripod or turning points, wind vibrations are natural errors
7. When distances are small which of the following error is negligible?
a) error due to defective joint
b) atmospheric refraction
c) wind vibrations
d) earth’s curvature
Explanation: The effect of curvature is to increase rod reading. When the distances are small the error is negligible.
8. Due to refraction, staff reading decreases.
a) True
b) False
Explanation: Due to refraction, the ray of light bends downwards in the form of a curve with its concavity towards the earth surface, thus decreases the staff readings
9. The degree of precision does not depend upon the type of instrument.
a) true
b) false
Explanation: The degree of precision depends upon the type of instrument, skill of observer, character of country, atmospheric conditions.
10. For a given instrument and atmospheric conditions, the precision depends upon the number of setups.
a) true
b) false
Explanation: For a given instrument and atmospheric conditions, the precision depends upon the number of setups and also upon the length of sights.