AP Physics 2: Waves and Geometric Optics

All rays that are parallel to the principle axis in a concave mirror reflects 

• Towards the focal point

• Away from the focal point

• Towards the center of curvature

• Away from the center of curvature

Answer explanation

All rays parallel to the principal axis in a concave mirror reflect towards the focal point due to the mirror's curvature, converging at that point after reflection.

g as a function of z means we plot

• A graph with z on the x-axis and g(z) on the y-axis.

• A bar graph comparing values of g and z without axes.

• A pie chart showing the relationship between g and z.

• A graph with g(z) on the x-axis and z on the y-axis.

Answer explanation

The correct choice is a graph with z on the x-axis and g(z) on the y-axis, as it represents g as a function of z. This format clearly shows how g changes with respect to z.

When looking at an object infinitely far away, the image forms at the

• focal point

• virtual focus

• image sensor

• lens center

Answer explanation

When observing an object at an infinite distance, the light rays converge at the focal point of the lens. This is where the image is formed, making 'focal point' the correct answer.

According to the Law of reflection, a light ray striking a mirror

• continues moving through the mirror in the same direction

• moves into the mirror at a slightly different angle

• bounces off the mirror toward the direction it came from

• bounces off the mirror at the same angle it hits.

Answer explanation

According to the Law of reflection, the angle at which a light ray hits a mirror (the angle of incidence) is equal to the angle at which it bounces off (the angle of reflection). Thus, it bounces off the mirror at the same angle it hits.

What type of image does this lens form?

• Virtual image

• Real Image

• No Image

Answer explanation

The lens forms a virtual image because it diverges light rays, making them appear to come from a location behind the lens. This type of image cannot be projected onto a screen, confirming it as a virtual image.

A 25.0 m object is placed 30.0 m from a convex lens, which has a focal length of 5.0 m. What is the distance of the image?

• 6 m

• 7 m

• 8 m

• 9 m

Answer explanation

Using the lens formula 1/f = 1/v - 1/u, where f = 5 m and u = -30 m, we find 1/v = 1/5 + 1/30. Solving gives v = 6 m. Thus, the image distance is 6 m.

Speed of light in a vacuum is

• represented by the symbol "c"

• 3.00 X10⁸ m/s 

• both answers are correct

Answer explanation

The speed of light in a vacuum is represented by the symbol 'c' and is approximately 3.00 x 10^8 m/s. Therefore, both statements are correct, making 'both answers are correct' the right choice.

What is the index of refraction of a refractive liquid if the angle of incidence in the air is 35 degrees and the angle of refraction is 14 degrees?

• 1.33

• 2.21

• 2.37

• 1.72

Answer explanation

Using Snell's Law, n1*sin(theta1) = n2*sin(theta2), where n1=1 (air). Plugging in values: 1*sin(35°) = n2*sin(14°). Solving gives n2 ≈ 2.37, which is the index of refraction of the liquid.

Which figure represents the path light takes through a converging lens?

• 
• 
• 
• 

Flat Mirrors have a magnification of...

• M < 1, Zooms Out

• M = 1, No Change

• M > 1, Zooms In

Answer explanation

Flat mirrors produce a magnification (M) of 1, meaning the image size is the same as the object size, resulting in no change in size. Therefore, the correct answer is M = 1, No Change.