Clock : Time :: Thermometer : ?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Temperature
The pair is an instrument and the quantity it measures: a clock measures time, and a thermometer measures temperature.
Why the other options are incorrect
Option (2) Heat — Incorrect. Heat is the energy that flows because of a difference in temperature; it is measured with a calorimeter, not read off a thermometer.
Option (3) Fever — Incorrect. Fever is a body temperature above normal, one thing a thermometer can show, not the quantity it measures.
Option (4) Kelvin — Incorrect. The kelvin is the SI unit of temperature, as the second is of time, not the quantity itself.