Physics Lecture Review: Waves, Light, EM Spectrum, Sound & Core Practicals

Comprehensive practice flashcards covering wave properties, light reflection and refraction, total internal reflection, electromagnetic spectrum, sound waves, oscilloscopes, and core physics practicals based on lecture notes.

What is the standard unit used for measuring angles in physics wave optics?

Degree ($^{\circ}$)

What unit is used to measure the frequency of a wave?

Hertz ($\text{Hz}$)

What is the standard SI unit for wavelength and distance?

Metre ($\text{m}$)

What unit is used to measure wave speed?

Metre per second ($\text{m/s}$)

What is the standard SI unit for time?

Second ($\text{s}$)

What is the fundamental SI base unit for mass?

Kilogram ($\text{kg}$)

What is the fundamental SI base unit for length?

Metre ($\text{m}$)

What is the fundamental SI base unit for time?

Second ($\text{s}$)

What is the fundamental SI base unit for electric current?

Ampere ($\text{A}$)

What is the fundamental SI base unit for temperature?

Kelvin ($\text{K}$)

What formula converts temperature from Celsius to Kelvin?

K = \text{^{\circ}C} + 273.15

What physical condition occurs at absolute zero ($0\,\text{K}$)?

Particle motion completely stops.

What numerical multiplier does the prefix Tera ($\text{T}$) represent?

$$\times 10^{12}$$

What numerical multiplier does the prefix Giga ($\text{G}$) represent?

$$\times 10^9$$

What numerical multiplier does the prefix Mega ($\text{M}$) represent?

$$\times 10^6$$

What numerical multiplier does the prefix Kilo ($\text{k}$) represent?

$$\times 10^3$$

What numerical multiplier does the prefix Centi ($\text{c}$) represent?

$$\times 10^{-2}$$

What numerical multiplier does the prefix Milli ($\text{m}$) represent?

$$\times 10^{-3}$$

What numerical multiplier does the prefix Micro ($\mu$) represent?

$$\times 10^{-6}$$

What numerical multiplier does the prefix Nano ($\text{n}$) represent?

$$\times 10^{-9}$$

What numerical multiplier does the prefix Pico ($\text{p}$) represent?

$$\times 10^{-12}$$

What is a scalar quantity?

A physical quantity that has magnitude (size) only.

What is a vector quantity?

A physical quantity that has both magnitude AND direction.

List six examples of scalar quantities given in the lecture notes.

Speed, distance, time, energy, temperature, mass.

List five examples of vector quantities given in the lecture notes.

Velocity, displacement, acceleration, force, momentum.

Is mass classified as a scalar or vector quantity?

Scalar quantity

Is velocity classified as a scalar or vector quantity?

Vector quantity

Is acceleration classified as a scalar or vector quantity?

Vector quantity

Is displacement classified as a scalar or vector quantity?

Vector quantity

Is temperature classified as a scalar or vector quantity?

Scalar quantity

How are oscillations oriented relative to the direction of energy transfer in transverse waves?

Oscillations (vibrations) are perpendicular ($90^{\circ}$) to the direction of energy transfer.

Name three examples of transverse waves listed in the notes.

Light waves, electromagnetic (EM) spectrum waves, water waves.

How are oscillations oriented relative to the direction of energy transfer in longitudinal waves?

Oscillations are parallel to the direction of energy transfer.

Name two examples of longitudinal waves listed in the notes.

Sound waves and ultrasound.

What is the definition of the amplitude of a wave?

The maximum displacement of a wave from its rest (undisturbed) position.

What is the definition of wavelength (lambda)?

The distance from one point on a wave to the exact same point on the next wave (e.g., crest to crest).

What is the definition of wave frequency (f)?

The number of complete waves passing a point per second (measured in Hertz, $\text{Hz}$).

What is the definition of wave period (T)?

The time taken for one complete wave cycle to pass (measured in seconds).

What is a wavefront?

A line connecting all adjacent points on a wave that are in phase (e.g., all the crests).

What do waves transfer as they travel through a medium?

Waves transfer energy and information without transferring matter.

What sound property is wave amplitude directly proportional to?

Volume

How does sound differ from light and water waves in terms of wave classification?

Sound is a longitudinal wave, whereas light and water waves are transverse waves.

What is the equation for wave speed (v) in terms of frequency (f) and wavelength (lambda)?

$$v = f \times \lambda$$

What is the formula for wave speed (v) in terms of wavelength (lambda) and period (T)?

$$v = \frac{\lambda}{T}$$

How do you calculate wavelength (lambda) if wave speed (v) and frequency (f) are known?

$$\lambda = \frac{v}{f}$$

How do you calculate frequency (f) if wave speed (v) and wavelength (lambda) are known?

$$f = \frac{v}{\lambda}$$

What equation links frequency (f) and time period (T)?

$$f = \frac{1}{T}$$

What equation links time period (T) and frequency (f)?

$$T = \frac{1}{f}$$

What are compressions in a longitudinal wave?

High-density regions where particles are squashed together.

What are rarefactions in a longitudinal wave?

Low-density regions where particles are spread apart.

Which feature of a transverse wave graph corresponds to a compression in a longitudinal wave?

A peak (or crest)

Which feature of a transverse wave graph corresponds to a rarefaction in a longitudinal wave?

A trough

In the diagram showing wave types, what structural regions make up a longitudinal wave?

Compressions and rarefactions.

In the transverse wave section of this diagram, what labels represent the top and bottom displacement extremes?

Crest (top displacement) and trough (bottom displacement).

What is the crest of a transverse wave?

The highest point of maximum positive displacement above the undisturbed rest position.

What is the trough of a transverse wave?

The lowest point of maximum negative displacement below the undisturbed rest position.

How is wavelength measured on a transverse wave graph?

From crest to crest, or trough to trough (or between any two identical points in phase).

How is wavelength measured on a longitudinal wave?

From the center of one compression to the center of the next compression.

Do particles in a medium move permanently forward with a passing wave?

No, particles oscillate around a fixed point; only energy and information are transferred.

If a wave has a frequency of $10\,\text{Hz}$, how many complete waves pass a fixed point per second?

$10$ complete waves

If the time period of a wave is $0.05\,\text{s}$, what is its frequency?

$$f = \frac{1}{0.05\,\text{s}} = 20\,\text{Hz}$$

Calculate the wave speed of a wave with frequency $5\,\text{Hz}$ and wavelength $2\,\text{m}$.

$$v = 5\,\text{Hz} \times 2\,\text{m} = 10\,\text{m/s}$$

Calculate the wavelength of a sound wave traveling at $300\,\text{m/s}$ with a frequency of $100\,\text{Hz}$.

$$\lambda = \frac{300\,\text{m/s}}{100\,\text{Hz}} = 3\,\text{m}$$

Calculate the period of a wave with a frequency of $500\,\text{Hz}$.

$$T = \frac{1}{500\,\text{Hz}} = 0.002\,\text{s}$$

Can light waves undergo reflection and refraction?

Yes, light waves are transverse waves that can be both reflected and refracted.

State the Law of Reflection.

Angle of Incidence ($i$) = Angle of Reflection ($r$).

How are angles of incidence and reflection always measured?

Between the light ray and the normal line.

What is the normal line in ray diagrams?

An imaginary line drawn perpendicular ($90^{\circ}$) to the surface where the light ray strikes.

What type of image is formed by a plane mirror?

A virtual image.

Why is an image formed in a plane mirror described as 'virtual'?

It cannot be projected on a screen because light rays only appear to meet behind the mirror.

Is the virtual image in a plane mirror upright or inverted?

Upright (correct way up).

How does the size of the virtual image in a plane mirror compare to the object?

The image is the same size as the object.

How does the distance of the virtual image behind a plane mirror compare to the object distance in front?

The image is formed the same distance behind the mirror as the object is in front.

What does 'laterally inverted' mean regarding a plane mirror image?

Left and right are swapped (e.g., $J \rightarrow L$).

In this reflection diagram, what do $\mathbf{i}^{\circ}$ and $\mathbf{r}^{\circ}$ represent relative to the magenta dashed line?

$i^{\circ}$ is the Angle of Incidence and $r^{\circ}$ is the Angle of Reflection, measured relative to the Normal line.

In this ray diagram, how are light paths extended behind the boundary surface to show the virtual image location?

Using dashed lines that extend backwards to cross at point X.

In this Doc Brown construction diagram, what indicates that the image formed behind the mirror is virtual?

Dotted lines show the construction of the virtual image behind the smooth side of the mirror.

What causes refraction when a wave passes from one medium into another?

Refraction occurs when a wave changes speed as it enters a medium of a different optical density.

What direction does light bend when passing from a less dense medium to a denser medium (e.g., Air to Glass)?

Light slows down and bends towards the normal.

What direction does light bend when passing from a denser medium to a less dense medium (e.g., Glass to Air)?

Light speeds up and bends away from the normal.

What happens to the direction of light when it enters a medium along the normal line ($0^{\circ}$ angle of incidence)?

It keeps going straight and does not bend, although its speed still changes.

Why does light not bend when incident perpendicular ($90^{\circ}$ to surface) along the normal?

Because refraction bending requires a change in speed across an angled wave front; along the normal, all parts change speed at the same time.

State Snell's Law equation for refractive index (n) using angles.

$$n = \frac{\sin(i)}{\sin(r)}$$

In Snell's Law $n = \frac{\sin(i)}{\sin(r)}$, what do 'i' and 'r' represent?

'i' is the angle of incidence, and 'r' is the angle of refraction.

Write the formula relating refractive index (n) and critical angle ($i_c$).

$\sin(i_c) = \frac{1}{n}$ or $n = \frac{1}{\sin(i_c)}$

Write the equation for refractive index (n) using the speed of light.

$$n = \frac{c}{v}$$

In the equation $n = \frac{c}{v}$, what do 'c' and 'v' represent?

'c' is the speed of light in a vacuum ($3 \times 10^8\,\text{m/s}$), and 'v' is the speed of light in that material.

What is the critical angle definition?

The angle of incidence for which the angle of refraction is $90^{\circ}$ (light travels along the boundary).

In this refraction diagram, how does the ray behave when passing from a rarer medium into a denser medium?

The incident ray bends towards the normal line as it enters the denser medium.

Calculate the refractive index (n) if angle of incidence $i = 30^{\circ}$ and angle of refraction $r = 19^{\circ}$ ($\sin(30^{\circ}) = 0.5$, $\sin(19^{\circ}) = 0.3256$).

$$n = \frac{\sin(30^{\circ})}{\sin(19^{\circ})} = \frac{0.5}{0.3256} \approx 1.535$$

If glass has a refractive index $n = 1.5$, calculate its critical angle ($i_c$).

$$\sin(i_c) = \frac{1}{1.5} \approx 0.667 \rightarrow i_c \approx 41.8^{\circ}$$

What is the approximate refractive index of air?

$$1.0$$

What is the approximate refractive index of glass?

$$1.5$$

What is the approximate refractive index of water?

$1.33$ (or $1.3$)

If the angle of incidence in air is $45^{\circ}$ and glass has $n = 1.5$, find $\sin(r)$.

$$\sin(r) = \frac{\sin(45^{\circ})}{1.5} = \frac{0.7071}{1.5} \approx 0.4714$$

Does the frequency of light change when it undergoes refraction entering a denser medium?

No, frequency remains unchanged; speed decreases and wavelength decreases.

What is optical density?

A property of a medium describing how much it slows down light passing through it.

What essential line must be drawn before measuring angles of incidence or refraction on a ray diagram?

A normal line drawn perpendicular ($90^{\circ}$) to the boundary interface.

What is Total Internal Reflection (TIR)?

The complete reflection of a light ray back inside an optically denser medium at the boundary with a less dense medium.

State the first condition required for Total Internal Reflection to occur.

Light must be traveling from an optically denser medium to a less dense medium (e.g., glass to air).