Question

Match the source of error with the corresponding correction in surveying with steel tape.

 

• A. P→1, Q→2, R→3
• B. P→1, Q→3, R→2
• C. P→2, Q→3, R→1
• D. P→2, Q→1, R→3

Hint:

In steel tape surveying, corrections depend on environmental factors such as sag, temperature, and the pull on the tape. Sag and pull corrections are typically negative or positive, and temperature correction can be either.

Answer 1

The Correct Option is C

Step 1: Sag correction.
Sag is the bending of the steel tape due to its own weight when not kept perfectly horizontal. This causes the measured length to be longer than the actual distance, and thus the correction is negative. Therefore, for (P), the correction is (2) Only Negative ($-$). 
Step 2: Temperature correction.
Temperature changes affect the length of the tape. If the temperature is higher than the standard temperature, the tape will expand, and if it is lower, the tape will contract. The correction can either be positive or negative depending on whether the temperature is above or below the standard temperature. Thus, for (Q), the correction is (3) Either positive or negative ($+$ or $-$). 
Step 3: Pull correction.
When the pull on the tape is greater than the standard pull, the tape elongates, making the measured length longer than the actual length. Therefore, the correction is positive, as it compensates for the increased length. Thus, for (R), the correction is (1) Only Positive ($+$).