Exploring Optics and Lenses

What is Fermat’s principle of least time?

• Light takes the longest path to reach its destination.

• Light moves faster in denser mediums.

• Light follows the path that takes the least time to travel between two points.

• Light travels in a straight line regardless of time.

Define the focal length of a lens.

• The focal length is the thickness of the lens.

• The focal length is the distance from the lens to the nearest object.

• The focal length is the angle at which light enters the lens.

• The focal length of a lens is the distance from the lens to its focal point.

What are the main differences between thick and thin lenses?

• Thick lenses are always used for reading, while thin lenses are used for distance vision.

• Thick lenses are thicker at the center and converge light more effectively, while thin lenses are nearly uniform in thickness and bend light less.

• Thick lenses are made of glass, while thin lenses are made of plastic.

• Thin lenses are thicker at the edges and diverge light more effectively than thick lenses.

Explain spherical aberration and its effects on image quality.

• Spherical aberration is an optical phenomenon that causes blurring and distortion in images due to light rays focusing at different points.

• Spherical aberration is a type of lens that improves color accuracy in images.

• Spherical aberration only occurs in telescopes and has no effect on cameras.

• Spherical aberration enhances image sharpness by focusing all light rays at a single point.

What is chromatic aberration and how can it be minimized?

• Chromatic aberration is a lens distortion causing color fringes; it can be minimized using achromatic lenses or software correction.

• Chromatic aberration is a feature of digital cameras.

• It can be enhanced by using single-element lenses.

• Chromatic aberration is a type of color blindness.

Describe the construction and working of Huygen’s eyepiece.

• Huygen's eyepiece is constructed from two convex lenses, designed to provide a clear and magnified image with minimal aberrations.

• Huygen's eyepiece uses a prism to reflect light for better clarity.

• Huygen's eyepiece is made from three lenses to enhance color correction.

• Huygen's eyepiece consists of a single concave lens for image magnification.

What is Rayleigh’s criterion for resolution?

• θ = 2.00(λ/D)

• θ = 0.61(λ/D)

• θ = 1.00(λ/D)

• θ = 1.22(λ/D)

How does a prism cause dispersion of light?

• A prism absorbs all wavelengths of light equally.

• A prism reflects light without changing its color.

• A prism causes dispersion of light by refracting different wavelengths at different angles.

• A prism emits light in a single wavelength only.

What are the advantages of using an eyepiece over a simple lens?

• Eyepieces provide higher magnification, wider field of view, adjustable focus, and reduced optical aberrations compared to simple lenses.

• Eyepieces are less durable and more prone to damage than simple lenses.

• Eyepieces only provide lower magnification than simple lenses.

• Eyepieces are heavier and more difficult to use than simple lenses.

What is the limit of resolution for the human eye?

• Approximately 0.2 millimeters at 20 feet.

• Approximately 1 millimeter at 10 feet.

• Approximately 0.5 millimeters at 30 feet.

• Approximately 0.1 millimeters at 5 feet.