The same telescope is used to obtain an image using light of the following wavelengths. Which of the images will have the poorest angular resolution?
a. blue
b. yellow
c. red
d. infrared
a
b
c
d
yellow
To determine which image will have the poorest angular resolution, we need to understand the concept of angular resolution.
Angular resolution refers to the ability of a telescope to distinguish between two closely spaced objects or to resolve fine details in an image. It is dependent on the wavelength of the light being observed or imaged.
The formula for calculating the angular resolution is given by:
θ = 1.22 * (λ / D)
Where:
θ is the angular resolution,
λ is the wavelength of light being observed,
D is the diameter of the telescope's aperture.
Now, let's analyze each option:
a. Blue wavelength: Blue light has a wavelength of around 400-500 nanometers. If we plug this value into the angular resolution formula, we see that the smaller the wavelength, the smaller the angular resolution. So, blue light will have a better angular resolution compared to longer wavelengths.
b. Yellow wavelength: Yellow light has a slightly longer wavelength than blue light, around 500-600 nanometers. The angular resolution for yellow light will be slightly worse compared to blue light due to its longer wavelength.
c. Red wavelength: Red light has an even longer wavelength, around 600-700 nanometers. As the wavelength increases, the angular resolution becomes worse. So, red light will have an even poorer angular resolution compared to blue or yellow light.
d. Infrared wavelength: Infrared light has an even longer wavelength, typically greater than 700 nanometers. Therefore, the angular resolution for infrared light will be the worst among the given options.
Therefore, the image with the poorest angular resolution will be the one obtained using infrared light (option d).