PHYSICS—LENSES QUESTIONS AND
ANSWERS WITH SOLUTIONS 2024
Lens - ANSWER When a piece of glass has just the right shape, it bends parallel rays of light so that they
cross and form an image.
Converging Lens - ANSWER Lens that is thicker in the middle and rays of light that are initially parallel are
made to converge.
Diverging Lens - ANSWER Thinner in the middle and the rays of light are made to diverge
Principal Axis - ANSWER Line joining the centers of curvature of its surfaces of a lens
Focal Point - ANSWER For a converging lens, the point at which a beam of light parallel to the principal
axis converges. For a diverging lens, the point from which such a beam appears to come.
Focal Plane - ANSWER A plane passing through either focal point of a lens that is perpendicular to the
principal axis. For a converging lens, any incident parallel beam of light converges to a point somewhere
on a focal plane. For a diverging lens, such a beam appears to come from a point on a focal plane
How does a lens affect light coming from the left compared to the right? - ANSWER A lens affects light
coming from the right in the same ways as light coming from the left; therefore, a lens has two focal
points and two focal planes.
Explains what happens when the lens of a camera is set for distant objects - ANSWER When the lens of a
camera is set for distant objects, the film is in the focal plane behind the lens in the camera.
Focal Length - ANSWER The distance between the center of a lens and either focal point
DRAW A DIAGRAM OF THE KEY FEATURES OF A CONVERGING LENS - ANSWER DRAW, LUKE
, Explain the relationship between the focal length and lens when the lens is thin and not - ANSWER When
the lens is thin, the focal lengths on either side are equal, even when the curvatures on the two sides are
not
Explain what happens to the angle of view when you are closer to an object, compared to farther away -
ANSWER An object far away is seen through a relatively small angle of view. When you are closer, the
same object is seen through a larger angle of view. This wider angle enables the perception of more
detail
When does magnification occur - ANSWER Magnification occurs when an image is observed through a
wider angle with the use of a lens than without the lens and allows more detail to be seen. A magnifying
glass is simply a converging lens that increased the angle of view and allows more detail to be seen
Explain what you do to use a magnifying glass - ANSWER When you use a magnifying glass, you hold it
close to the object you wish to see magnified. This is because a converging lens will magnify only when
the object is between the focal point and the lens. The magnified image will be father from the lens than
the object, and it will be right side up.
Real image - ANSWER an image that is formed by converging light rays and that can be displayed on a
screen
What happens when a diverging lens is used alone, etc. - ANSWER When a diverging lens is used alone,
the image is ALWAYS virtual, right-side up, and small than the object. When you look at an object to be
photographed through the viewfiner, you see a right-side up virtual image that approximates the same
proportions as the photograph to be taken
Ray Diagrams - ANSWER A diagram showing rays that can be drawn to determine the size and location of
an image formed by a mirror or lens
To construct a ray diagram what must be known? - ANSWER To construct a ray diagram, the size and
location of the object, its distance from the center of the lens, and the focal length of the lens must be
known.
What do the moving patterns of bright lines on the bottom of swimming pools result from? - ANSWER
The moving patterns of bright lines on the bottom of a swimming pool results from the uneven surfaces
of water, which behaves as a moving blanket of lenses
ANSWERS WITH SOLUTIONS 2024
Lens - ANSWER When a piece of glass has just the right shape, it bends parallel rays of light so that they
cross and form an image.
Converging Lens - ANSWER Lens that is thicker in the middle and rays of light that are initially parallel are
made to converge.
Diverging Lens - ANSWER Thinner in the middle and the rays of light are made to diverge
Principal Axis - ANSWER Line joining the centers of curvature of its surfaces of a lens
Focal Point - ANSWER For a converging lens, the point at which a beam of light parallel to the principal
axis converges. For a diverging lens, the point from which such a beam appears to come.
Focal Plane - ANSWER A plane passing through either focal point of a lens that is perpendicular to the
principal axis. For a converging lens, any incident parallel beam of light converges to a point somewhere
on a focal plane. For a diverging lens, such a beam appears to come from a point on a focal plane
How does a lens affect light coming from the left compared to the right? - ANSWER A lens affects light
coming from the right in the same ways as light coming from the left; therefore, a lens has two focal
points and two focal planes.
Explains what happens when the lens of a camera is set for distant objects - ANSWER When the lens of a
camera is set for distant objects, the film is in the focal plane behind the lens in the camera.
Focal Length - ANSWER The distance between the center of a lens and either focal point
DRAW A DIAGRAM OF THE KEY FEATURES OF A CONVERGING LENS - ANSWER DRAW, LUKE
, Explain the relationship between the focal length and lens when the lens is thin and not - ANSWER When
the lens is thin, the focal lengths on either side are equal, even when the curvatures on the two sides are
not
Explain what happens to the angle of view when you are closer to an object, compared to farther away -
ANSWER An object far away is seen through a relatively small angle of view. When you are closer, the
same object is seen through a larger angle of view. This wider angle enables the perception of more
detail
When does magnification occur - ANSWER Magnification occurs when an image is observed through a
wider angle with the use of a lens than without the lens and allows more detail to be seen. A magnifying
glass is simply a converging lens that increased the angle of view and allows more detail to be seen
Explain what you do to use a magnifying glass - ANSWER When you use a magnifying glass, you hold it
close to the object you wish to see magnified. This is because a converging lens will magnify only when
the object is between the focal point and the lens. The magnified image will be father from the lens than
the object, and it will be right side up.
Real image - ANSWER an image that is formed by converging light rays and that can be displayed on a
screen
What happens when a diverging lens is used alone, etc. - ANSWER When a diverging lens is used alone,
the image is ALWAYS virtual, right-side up, and small than the object. When you look at an object to be
photographed through the viewfiner, you see a right-side up virtual image that approximates the same
proportions as the photograph to be taken
Ray Diagrams - ANSWER A diagram showing rays that can be drawn to determine the size and location of
an image formed by a mirror or lens
To construct a ray diagram what must be known? - ANSWER To construct a ray diagram, the size and
location of the object, its distance from the center of the lens, and the focal length of the lens must be
known.
What do the moving patterns of bright lines on the bottom of swimming pools result from? - ANSWER
The moving patterns of bright lines on the bottom of a swimming pool results from the uneven surfaces
of water, which behaves as a moving blanket of lenses
