If a is the center of the circle which of these is/are RADII? a dc

b ef

c a. f

d ea

e cf

the answer is b

explanation:

infrared radiation has wavelength in the range between 700 nm and 1 mm. lets' convert these values into scientific notation, keeping in mind that:

let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

the higher value is:

so, the range of wavelength of infrared radiation is:

what are the answer choices given for this problem?