NEETPhysicsUnits and Dimensions
What is the SI unit of thermal resistance?
Options
- AK J ⁻¹
- BW m ⁻¹ K ⁻¹
- CW K ⁻¹
- DK W ⁻¹
Correct answer
D. K W ⁻¹
Step-by-step solution
Thermal resistance ( R_ th ) is defined using the analogy to Ohm's law for heat transfer: H = T R_ th where H is the heat current (rate of heat flow) and T is the temperature difference. Rearranging the formula gives: R_ th = T H The SI unit of temperature difference ( T ) is Kelvin ( K ). The SI unit of heat current ( H = Q t ) is Watt ( W ). Therefore, the SI unit of thermal resistance is K W ⁻¹ . Answer: K W ⁻¹