D42 QUIZ OF THE DAY

What is the nominal length of a 30 m chain as per IS:1492-1970?

• 29.95 m
• 30.00 m
• 30.05 m
• 30.10 m

Answer explanation

According to IS:1492-1970, the nominal length of a 30 m chain is exactly 30.00 m.

Which among the following is used for setting perpendicular lines in chain surveying?

• Optical square
• Line ranger
• Plumb bob
• Arrow

Answer explanation

Optical square helps in setting perpendicular lines using the principle of double reflection.

What is the typical spacing of tallies on a 30 m metric chain?

• Every 2 m
• Every 5 m
• Every 10 m
• Every 15 m

Answer explanation

Tallies are placed every 5 m to mark intermediate distances on a metric chain.

Assertion: Steel tapes are used for precise measurements. Reason: Chains elongate over time due to wear.

• Both A and R are true and R is the correct explanation
• Both A and R are true but R is not the explanation
• A is true but R is false
• A is false but R is true

Answer explanation

Steel tapes are more accurate and don’t elongate like chains due to wear and tear.

Statement 1: Chain surveying is suitable for large-scale maps. Statement 2: It is ideal where high precision is required.

• Only Statement 1 is true
• Only Statement 2 is true
• Both statements are true
• Both statements are false

Answer explanation

Chain surveying is for large-scale mapping but not suitable for highly precise work.

Which error in chain surveying occurs due to incorrect length of chain?

• Personal error
• Compensating error
• Instrumental error
• Cumulative error

Answer explanation

Error due to incorrect chain length is cumulative and affects the entire measurement.

What is the primary purpose of tie lines in chain surveying?

• Divide survey area into triangles
• Avoid long offsets
• Check the accuracy of the framework
• Mark details

Answer explanation

Tie lines are provided to avoid taking long offsets and to connect different parts of the survey.

Which of the following helps in measuring offsets at right angles?

• Offset rod
• Cross staff
• Plumb bob
• Ranging rod

Answer explanation

Cross staff is specifically used to set out right angles in field.

Which method of ranging is used when both end stations are not intervisible?

• Direct ranging
• Reciprocal ranging
• Random ranging
• Optical ranging

Answer explanation

Reciprocal ranging is used when end points are not intervisible due to obstructions.

How many links are there in a 30 m metric chain?

• 100
• 120
• 150
• 180

Answer explanation

Each link is 0.2 m; So, 30/0.2 = 150 links.