When we sit at a camp fire, objects beyond the fire are seen swaying. Give the reason for it. (AS7)

• Above the fire, the temperature of the atmosphere is higher.

• And as we know that at constant pressure, the density and temperature is inversely related

• So the density above the fire is decreased.

• Due to this change in density the refractive index of the surrounding air, the angle of reflection and angle of deviation changes.

Thus the object beyond the fire is seen swaying.