Geometric Optics and Reflection

For calculations with lenses where the thickness cannot be neglected, the lensmaker's equation must be used. What is it?

1/f = (n-1)*(1/r1 - 1/r2)

To find the focal length of multiple lenses in contact, you must use this equation:

1/f = 1/f1 + 1/f2 + 1/f3 ...

In spherical mirrors, if the image has a positive distance, it is a __________ image, which implies that the image is __________ the mirror. A) real, in front of B) real, behind C) virtual, in front of D) virtual, behind

A) real, in front of

In lenses, if the image has a positive distance, it is a __________ image and the image is on the ____________ side of the lens as the light source. A) real, opposite B) virtual, opposite C) real, same D) virtual, same

A) real, opposite

In spherical mirrors and lenses, if the absolute value of the magnification is less than 1, the image is __________. A) reduced B) enlarged C) inverted D) upright

A) reduced

__________ is the bending of light as it passes from one medium to another and changes speed. A) refraction B) reflection C) diffraction D) deflection

A) refraction

If f, the focal length, of a lens is positive, then the lens is ____________ and if it is negative, then the lens is __________. A) convex (diverging); concave (converging) B) convex (converging); concave (diverging) C) concave (diverging); convex (converging) D) concave (converging); convex (diverging)

B) convex (converging); concave (diverging)

If r, the radius, of a lens is positive, then the lens is ____________ and if it is negative, then the lens is __________. A) convex (diverging); concave (converging) B) convex (converging); concave (diverging) C) concave (diverging); convex (converging) D) concave (converging); convex (diverging)

B) convex (converging); concave (diverging)

In spherical mirrors and lenses, if the absolute value of the magnification is greater than 1, the image is __________. A) reduced B) enlarged C) inverted D) upright

B) enlarged

__________ is the rebounding of incident light waves at the boundary of a medium. A) refraction B) reflection C) diffraction D) deflection

B) reflection

Which of the following best describes total internal reflection? A) refraction that results in no change in the incident angle B) refraction that results in reflection C) reflection that results in light reflecting back perfectly upon the same path D) reflection that results in refraction

B) refraction that results in reflection

Converging lenses are __________ at the center, and are __________. A) thicker; concave B) thicker; convex C) thinner; concave D) thinner; convex

B) thicker; convex

In the lab, your first object is 10 inches high, the first image is 5 inches high, and the second image is 2 inches high. Your lab instructor asks you to calculate the overall magnification for the two lens setup. What is the answer? A) 0.8 B) 0.5 C) 0.2 D) 0.1

C) 0.2

In spherical mirrors lenses, if the magnification is negative, the image is __________. A) reduced B) enlarged C) inverted D) upright

C) inverted

Diverging lenses are __________ at the center, and are __________. A) thicker; concave B) thicker; convex C) thinner; concave D) thinner; convex

C) thinner; concave

If f, the focal length, of a mirror is positive, then the mirror is ____________ and if it is negative, then the mirror is __________. A) convex (diverging); concave (converging) B) convex (converging); concave (diverging) C) concave (diverging); convex (converging) D) concave (converging); convex (diverging)

D) concave (converging); convex (diverging

If r, the radius, of a mirror is positive, then the mirror is ____________ and if it is negative, then the mirror is __________. A) convex (diverging); concave (converging) B) convex (converging); concave (diverging) C) concave (diverging); convex (converging) D) concave (converging); convex (diverging)

D) concave (converging); convex (diverging)

In spherical mirrors and lenses, if the magnification is positive, the image is __________. A) reduced B) enlarged C) inverted D) upright

D) upright

In spherical mirrors, if the image has a negative distance, it is a __________ image, which implies that the image is __________ the mirror. A) real, in front of B) real, behind C) virtual, in front of D) virtual, behind

D) virtual, behind

In lenses, if the image has a negative distance, it is a __________ image and the image is on the ____________ side of the lens as the light source. A) real, opposite B) virtual, opposite C) real, same D) virtual, same

D) virtual, same

TRUE or FALSE: In a ray diagram, a line that is drawn parallel to the axis will be reflected back through the focal point in a convex mirror.

FALSE concave (converging)

TRUE or FALSE: The focal length of diverging mirrors and lenses will always be positive.

FALSE negative

TRUE or FALSE: All angles in optics are measured from the medium.

FALSE normal

TRUE or FALSE: Lenses reflect light, and mirrors refract it.

FALSE opposite

TRUE or FALSE: Plane mirrors never create virtual images.

FALSE always

How is power of a lens found?

P = 1/f measured in diopters f in meters

To find the power of multiple lenses in contact, you must use this equation:

P = P1 + P2 + P3 ...

TRUE or FALSE: Any time an object is at the focal point of a converging mirror, the reflected rays will be parallel, and the image will be at infinity.

TRUE

TRUE or FALSE: For plane mirrors, i = -o.

TRUE

TRUE or FALSE: People who are nearsighted (can see near objects) need diverging lenses, and people who are farsighted (can see far objects) need converging lenses.

TRUE

TRUE or FALSE: Plane mirrors cause neither convergence or divergence of reflected light rays.

TRUE

TRUE or FALSE: Rectilinear propagation describes how light travels in a straight line in a homogenous medium.

TRUE

TRUE or FALSE: Single diverging (convex) mirrors only form virtual, upright, and reduced images, regardless of the objects position.

TRUE

TRUE or FALSE: The focal length of all spherical mirrors is f = r/2.

TRUE

TRUE or FALSE: The focal length of converging mirrors and lenses will always be positive.

TRUE

The distance of the object from the mirror, o, is negative when the object is __________ the mirror, and positive when the object is ___________ the mirror.

behind in front of

What is spherical abberation?

blurring of the periphery of an image bc of inadequate reflection of parallel beams at the edge of a mirror or inadequate refraction of parallel beams at the edge of a lens

What are the two types of spherical mirrors?

concave and convex

Concave mirrors are called __________ mirrors, and convex mirrors are called ________ mirrors.

converging diverging

__________ is when various wavelengths of light separate from each other.

dispersion

What is chromatic abberation?

dispersive effect within spherical lens splitting of white light, halo around images

Total internal reflection, a phenomenon in which all the light incident on a boundary is reflected back into the original material, results with any angle incidence _________.

greater than the critical angle, θc

What is the equation to find magnification?

m = -i/o

For lenses not in contact, the magnification of the image can be found as:

m = m1*m2*m3....

What are the scientific terms for nearsightedness and farsightedness?

myopia hyperopia

What is the equation to find the index of refraction, n?

n = c/v

What is Snell's law?

n1sinθ1 = n2sinθ2

The center of curvature is located a distance equal to the ____________ from the vertex of the mirror.

radius of curvature

What makes an image real or virtual?

real = light actually converges at the position of the image virtual = light only appears to be coming from the position of the image but does not actually converge there

What is the focal length?

the distance between the focal point (F) and the mirror

When is the critical angle reached?

when θ2 = 90° in snell's law θc = sin ^-1 (n2/n1)