Physics - Heat & Thermo Question with Solution | TestHub
Two thermometers are constructed in the same way except that one has a spherical bulb and the other has a cylindrical bulb of same radius. Which one will respond faster to temperature changes. Evaluate the following statements.
Statement I: The spherical bulb responds faster when the cylinder length exceeds its diameter, assuming identical heat-transfer conditions.
Statement II: The cylindrical bulb is always faster for any length.
Options:
Answer:
Solution:
Response time depends on how much liquid must be heated per unit area through which heat enters. For the same radius , a sphere has , while a cylinder of length (with ends) has , which exceeds whenever . The cylindrical bulb holds more liquid per unit surface area, so it warms more slowly. The spherical bulb responds faster (assuming the cylinder is longer than its diameter). Statement I is true and Statement II false. Correct option: (B).
