Physics - Heat & Thermo Question with Solution | TestHub

PhysicsHeat & ThermoThermal ExpansionMedium2 minQB
PhysicsMediumassertion reason

Assertion: A thermometer in direct sunlight need not read the air temperature.

Reason: Its reading is its own equilibrium temperature, set by absorbed radiation and heat losses.

Options:

Answer:
A
Solution:

It measures its own temperature. The bulb absorbs sunlight and gains heat, and loses heat to the air by conduction, convection and radiation; it settles where gain equals loss, which is above the air temperature (and nowhere near the Sun's temperature). It is not the air temperature; measure air temperature in shade with ventilation. Both are true. The Reason gives the physical cause of the Assertion. Correct option: (A).

Subject:PhysicsTopic:Heat & ThermoSubtopic:Thermal Expansion
⏱ 2mℹ️ Source: QB

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