What type of lens is thicker at the center than at the edges?
a) Concave lens
b) Convex lens
c) Biconcave lens
d) Plano-convex lens
In a concave lens, where is the image formed for an object placed at infinity?
a) At the focal point
b) At the center of curvature
c) At infinity
d) Between the focal point and the lens
What is the focal length of a concave lens?
a) Positive
b) Negative
c) Zero
d) Infinite
For an object placed at the focus of a convex lens, where will the image be formed?
a) At infinity
b) At the focal point
c) At twice the focal length
d) At the focus of the lens
What type of image is formed by a convex lens when the object is placed beyond the focal length?
a) Virtual, upright, and diminished
b) Real, inverted, and diminished
c) Real, inverted, and magnified
d) Virtual, upright, and magnified
Which lens type is used in a magnifying glass?
a) Concave lens
b) Convex lens
c) Cylindrical lens
d) Spherical lens
What happens to the image formed by a concave lens?
a) It is always virtual, upright, and diminished
b) It is always real and inverted
c) It is always real, upright, and magnified
d) It is always virtual, inverted, and diminished
Where is the image formed by a convex lens when the object is at the focus?
a) At the focus
b) At infinity
c) At twice the focal length
d) At the optical center
What is the relationship between the focal length (f), object distance (u), and image distance (v) in a lens?
a) 1/f = 1/v + 1/u
b) f = u + v
c) f = u – v
d) 1/f = 1/v – 1/u
For a convex lens, when the object is placed at twice the focal length, what is the nature of the image?
a) Virtual and upright
b) Real and inverted
c) Real and upright
d) Virtual and inverted
If the object is placed at the focal point of a concave lens, where will the image be formed?
a) At infinity
b) At the focus
c) At twice the focal length
d) At the lens itself
What type of image does a convex lens produce when the object is placed closer than the focal point?
a) Real, inverted, and diminished
b) Virtual, upright, and magnified
c) Virtual, inverted, and diminished
d) Real, upright, and magnified
In a convex lens, when the object is beyond twice the focal length, the image will be:
a) Real and diminished
b) Virtual and magnified
c) Real and magnified
d) Virtual and diminished
Which of the following is the principal focus of a lens?
a) The point where light rays parallel to the principal axis converge or appear to diverge
b) The center of the lens
c) The point where all light rays pass through
d) The point where the object is located
What is the formula for magnification in terms of image distance and object distance for a lens?
a) Magnification = v/u
b) Magnification = u/v
c) Magnification = v + u
d) Magnification = u – v
What type of image is formed by a concave lens when the object is placed at a distance greater than the focal length?
a) Real, inverted, and diminished
b) Virtual, upright, and magnified
c) Real, inverted, and magnified
d) Virtual, upright, and diminished
Which of the following statements is true for a concave lens?
a) It forms a virtual image, regardless of the object’s distance
b) It always forms a real, inverted image
c) It forms an image that is always smaller and upright
d) It always forms a real, magnified image
In a concave lens, where is the image formed if the object is very far away?
a) At the focal point
b) At the optical center
c) At infinity
d) At the center of curvature
If the image formed by a convex lens is real and magnified, where must the object be placed?
a) At the focus
b) At twice the focal length
c) Between the focal point and the lens
d) At infinity
What is the term for the point on the principal axis where parallel rays of light converge after passing through a lens?
a) Optical center
b) Focal point
c) Center of curvature
d) Principal axis
Which of the following best describes a virtual image?
a) It can be projected on a screen
b) It is formed by diverging rays of light
c) It is always upright and diminished
d) It is always inverted and magnified
In a convex lens, what happens to the image when the object is placed beyond twice the focal length?
a) The image is real, inverted, and diminished
b) The image is real, inverted, and magnified
c) The image is virtual, upright, and diminished
d) The image is real, upright, and magnified
What is the effect of increasing the curvature of a lens?
a) It decreases the focal length
b) It increases the focal length
c) It makes the lens thicker
d) It makes the lens flatter
What is the shape of the principal axis in a lens?
a) Curved
b) Straight
c) Wavy
d) Zigzag
What is the image formed by a concave lens when the object is at the focal point?
a) Virtual and magnified
b) Real and diminished
c) Real and inverted
d) Virtual and diminished
How does a concave lens affect light rays?
a) It converges light rays
b) It diverges light rays
c) It focuses light rays to a point
d) It does not affect light rays
