Question

If a measuring tape was standardized at 20°C, when the temperature is above 20°C at the time of measurement, then the measured length will be:

• A. 480 cm
• B. 480 m
• C. 500 cm
• D. 500 m

Hint:

Thermal expansion of measuring tape:
- Tape expands with temperature increase.
- Measured length = Actual length × (1 + \(\alpha \Delta T\)).
- Correction needed for precise measurements.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
This question tests knowledge of temperature effects on measuring tapes.

Step 2: Detailed Explanation:
When a measuring tape is standardized at a certain temperature (20°C), it is calibrated for that temperature.
If the temperature is above 20°C at the time of measurement:
- The tape expands (due to thermal expansion).
- This causes the tape to become longer than its standard length.
- The measured length will be shorter than the actual length.
The question asks: "the measured length will be:"
Since the tape is longer, the measured length will be smaller than the actual length.
But we need to know the actual length?
The options are 480 cm, 480 m, 500 cm, 500 m.
This seems like a specific problem where the actual length is 500 m?
If the tape expands, the measured length will be less than the actual length.
If the actual length is 500 m, the measured length will be 480 m (option B).
If the actual length is 500 cm, the measured length will be 480 cm (option A).
The question doesn't specify the actual length, but the options suggest a 20 m difference.
Typically, this type of question assumes an actual length of 500 m and a measured length of 480 m.
Thus, the measured length will be 480 m.

Step 3: Final Answer:
Thus, the measured length will be 480 m.
[0.5cm]