AP Physics 2 ray diagrams cheat sheet

Ray diagram for a concave mirror

1. Object outside F: Inverted, reduced image. 2. Object at F: No image. 3. Object between F and mirror: Upright, enlarged image.

Difference between real and virtual images

Real images: Can be projected on a screen, inverted. Virtual images: Cannot be projected, upright.

Lens formula for thin lenses

The lens formula is given by: \frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i} Where $\displaystyle f$ is focal length, $\displaystyle d_o$ is object distance, $\displaystyle d_i$ is image distance.

True or False: Convex lenses always produce virtual images.

False: Convex lenses can produce both real (when object is outside focal point) and virtual images (when object is inside focal point).

Fill in the blank: Focal length of a concave lens is ___

Negative.

Concave vs. Convex Mirrors

Concave: Converging, can produce real and virtual images. Convex: Diverging, always produces virtual images.

How to determine image location in ray diagrams?

1. Draw a ray parallel to the principal axis. 2. Draw a ray through the focal point. 3. The intersection of rays gives the image location.

What happens when light enters a denser medium?

It bends towards the normal; speed decreases.

Define critical angle.

The angle of incidence that results in total internal reflection, given by: heta_c = \frac{sin^{-1}(n_2/n_1)} Where $\displaystyle n_1$ is the refractive index of the first medium.

What does the term 'magnification' refer to?

The ratio of image height to object height: M = \frac{h_i}{h_o} = -\frac{d_i}{d_o} Where $\displaystyle h_i$ is image height, $\displaystyle h_o$ is object height.

Cause → Effect: Light passing through a prism.

Cause: Refraction at different angles. Effect: Dispersion into a spectrum of colors.

Example of ray diagram for a convex lens.

1. Object beyond 2F: Real, inverted image between F and 2F. 2. Object at 2F: Real, inverted image at 2F (same size). 3. Object between F and lens: Virtual, upright image on the same side.

What is the lens formula?

The lens formula is given by: \frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i} where $\displaystyle f$ is the focal length, $\displaystyle d_o$ is the object distance, and $\displaystyle d_i$ is the image distance.

True or False: A virtual image is always upright.

True. A virtual image formed by a lens or mirror is always upright and cannot be projected onto a screen.

Define magnification in optics.

Magnification ($\displaystyle M$) is defined as: M = \frac{h_i}{h_o} = -\frac{d_i}{d_o} where $\displaystyle h_i$ is the image height and $\displaystyle h_o$ is the object height.

What is a concave lens?

A concave lens is diverging. It has a negative focal length and causes parallel rays of light to diverge as if they originated from a focal point.

Complete the formula: $\displaystyle M = -\frac{d_i}{d_o}$; $\displaystyle d_i$ is...

...the image distance. Note: $\displaystyle d_i$ is positive for real images and negative for virtual images.

What type of image does a convex mirror produce?

A convex mirror always produces a virtual, upright, and reduced image regardless of the object's position.

Comparison: Real vs. Virtual Images

Real Images: - Can be projected on a screen - Inverted - Formed by converging light rays Virtual Images: - Cannot be projected - Upright - Formed by diverging light rays.

How does increasing object distance affect image size?

As the object distance ($\displaystyle d_o$) increases for a convex lens: - Image size decreases - Image moves closer to the focal point.

Calculate the magnification for an object 10 cm away, image at 5 cm.

Given: - $\displaystyle d_o = 10$ cm, - $\displaystyle d_i = 5$ cm. Using $\displaystyle M = -\frac{d_i}{d_o}$: M = -\frac{5}{10} = -0.5 (image is reduced and inverted).

True or False: All lenses can produce both real and virtual images.

False. Only convex lenses can produce both real and virtual images; concave lenses only produce virtual images.

What is the significance of the focal point?

The focal point is where parallel rays converge (convex lens) or appear to diverge from (concave lens). It is crucial in lens calculations.

Identify the type of mirror: produces virtual images that are larger.

This describes a concave mirror, which can produce larger virtual images when the object is placed within the focal length.