Answer:
1) blue end of the spectrum
2) area of aperture
Explanation:
1) The electromagnetic spectrum encompases a wide range of frequency (ν) and wavelength (λ) that includes gamma rays, x-rays, ultra violet(UV), visible, infra red (IR), microwaves and radiowaves. The wavelength increases from gamma rays to radio waves.
The wavelength perceivable by human eyes lies in the UV-visible region which extends from 380 nm in the blue to 740 nm in the red.The shortest wavelengths occur in the blue end of the spectrum which also have the highest energy. In contrast, longer wavelengths occur on the red which have lower energy.
2) The light gathering capacity of a telescope is dependent upon its area of aperture. Larger the area, greater is the light gathering power which implies that the telescope has the capability of detecting weak or faint objects.
The area of the aperture is essentially the area of the objective of the telescopic lens which is given as:
\(area = \frac{\pi*D^{2} }{4}\)
where D = diameter of the lens
