Question

which image exclusively represents the principle of radiation? a iv b iii c ii

Explanation:

Step1: Recall heat - transfer methods

Conduction is heat transfer through direct contact, convection is heat transfer through fluid motion, and radiation is heat transfer through electromagnetic waves.

Step2: Analyze each image

Image I shows a pot on a stove with arrows indicating fluid motion inside the pot, which is convection. Image II shows a person near a fire, which has some conduction and convection along with radiation. Image III shows the sun emitting rays towards the earth, which is an example of radiation as the sun's heat reaches the earth through electromagnetic waves in a vacuum. Image IV shows a person near a radiator, which involves some convection and radiation but also conduction if the person touches the radiator.

Answer:

B. III