Question

The coefficient of thermal expansion of invar tape for \(1^\circ C\) rise is

• A. \(0.6\times 10^{-6}\)
• B. \(0.7\times 10^{-6}\)
• C. \(0.3\times 10^{-6}\)
• D. \(0.9\times 10^{-6}\)

Hint:

Invar tape is preferred for precise measurement because its coefficient of thermal expansion is very small.

Answer 1

The Correct Option is A

Concept:
Invar tape is used in precise surveying work because it has a very low coefficient of thermal expansion.

Step 1: Ordinary steel tapes expand appreciably with temperature change.

Step 2: Invar tape is made from an alloy having very small thermal expansion.

Step 3: Therefore, errors due to temperature changes are much smaller in invar tape.

Step 4: The coefficient of thermal expansion of invar tape for \(1^\circ C\) rise is: \[ 0.6\times 10^{-6} \] \[ \boxed{0.6\times 10^{-6}} \]