Question

The Kirchhoff’s law leads to the conclusion that the good radiators of thermal radiations are:
(A) Good absorbers
(B) Bad absorbers
(C) Thermal insulators
(D) None of these

Answer 1

Hint
Kirchhoff’s Voltage Law or KVL, states that in any closed loop network, the total voltage around the loop is equal to the sum of all the voltage drops within the same loop which is also equal to zero. In other words, the algebraic sum of all voltages within the loop must be equal to zero. Kirchhoff's laws are used to help us understand how current and voltage work within a circuit. They can also be used to analyse complex circuits that can't be reduced to one equivalent resistance using what you already know about series and parallel resistors. Based on this concept we have to solve this question.

Complete step by step answer
Kirchhoff’s Law states that the emissivity of a surface is equal to its absorbance, where the absorbance of a surface is the ratio of the radiant power absorbed to the radiant power incident on the surface. It concludes that good radiators of thermal radiations are good absorbers.

Therefore, option (A) is the correct answer.

Note
We know thermal radiation is electromagnetic radiation that is emitted by a body as a result of its temperature. All objects with a temperature above absolute zero emit thermal radiation in a spectrum of wavelengths. Thermal radiation takes place when the entire atoms are heated so that kinetic energy is released, causing the entire atoms to vibrate. The energy accumulated through vibration is consequently released as electromagnetic radiation/light. Damage as a result of thermal radiation is much more severe towards humans. The very intense heating from the fireball causes "flash burns," where the more thermal radiation absorbed, the worse the burn becomes.