Quiz on Thin Converging Lenses

What is the principal focus of a convex lens?

• The point where light rays diverge
• The point where parallel rays converge
• The center of the lens
• The point where light rays are absorbed

If a ray of light passes through the optical center of a convex lens, what happens to it?

• It is refracted at an angle
• It passes straight through without deviation
• It is absorbed by the lens
• It diverges away from the lens

What does the focal length of a lens represent?

• The distance from the lens to the object
• The distance from the lens to the image
• The distance from the optical center to the principal focus
• The thickness of the lens

Which of the following statements about magnification is true?

• Magnification is always greater than 1
• Magnification has units of measurement
• If M > 1, the image is diminished
• If M < 1, the image is smaller than the object

When drawing a ray diagram for a convex lens, which ray is refracted through the principal focus?

• A ray passing through the optical center
• A ray parallel to the principal axis
• A ray passing through the principal focus
• A ray diverging from the lens

In an experiment to determine the focal length of a lens, what should be done to ensure a clear image?

• Use a bright light source
• Increase the distance from the lens to the object
• Use a colored filter
• Decrease the size of the lens

What type of image is formed by a convex lens when the object is placed beyond the focal length?

• Virtual and upright
• Real and inverted
• Virtual and inverted
• Real and upright

Which of the following describes a real image formed by a convex lens?

• It cannot be projected onto a screen
• It is always larger than the object
• It is inverted and can be projected onto a screen
• It is always smaller than the object

What is the effect of increasing the object distance on the size of the image formed by a convex lens?

• The image size increases
• The image size decreases
• The image size remains the same
• The image becomes virtual

If the distance of the object from a convex lens is halved, what happens to the distance of the image from the lens?

• It doubles
• It remains the same
• It is halved
• It becomes zero