| The difference in the distance travelled by two waves. | Path Difference |
| What is path difference? | The difference in the distance travelled by two waves. |
| A light source that has the same frequency, wavelength, and a fixed phase difference. | Coherent Light Source |
| What defines a coherent light source? | It has the same frequency, wavelength, and a fixed phase difference. |
| A type of light that is coherent and monochromatic, meaning it emits a single or small range of wavelength(s). | Lasers |
| Why are lasers used in diffraction experiments? | Because they are coherent, monochromatic, and form clear interference patterns. |
| Demonstrates interference of light from two sources using either two coherent light sources or a single source and a double slit to form an interference pattern. | Young's Double Slit Experiment |
| What does Young's double slit experiment demonstrate? | It demonstrates interference of light from two sources, forming an interference pattern. |
| If using a light bulb, place a single slit before the double slit to fix the path difference, and use a filter to make the light monochromatic. | Creating Coherence with a Light Bulb |
| How can you make a light bulb's light coherent for the double slit experiment? | Use a single slit to fix the path difference and a filter to make the light monochromatic. |
| When coherent light passes through slits about the size of the wavelength, it diffracts and creates a pattern of light and dark fringes. | Diffraction of Light |
| What happens when coherent light passes through slits in the double slit experiment? | The light diffracts, creating a pattern of light and dark fringes. |
| Formed where light meets in phase and constructive interference occurs. This happens where the path difference is a whole number of wavelengths (nλ). | Light Fringes |
| Where do light fringes form in Young's double slit experiment? | Where light meets in phase, causing constructive interference, with a path difference of nλ. |
| Formed where light meets out of phase and destructive interference occurs, with a path difference of (n + ½)λ. | Dark Fringes |
| Where do dark fringes form in Young's double slit experiment? | Where light meets out of phase, causing destructive interference, with a path difference of (n + ½)λ. |
| The formula is where w is fringe spacing, λ is the wavelength, D is the distance between the screen and slits, and s is the slit separation. | Fringe Spacing Formula |
| What is the formula for fringe spacing in Young's double slit experiment? | w = λD/s, where w is fringe spacing, λ is the wavelength, D is the distance between the screen and slits, and s is the slit separation. |
| Using white light gives wider maxima and a less intense diffraction pattern. | White Light Diffraction Pattern |
| What does using white light in diffraction experiments produce? | Wider maxima and a less intense pattern. |
| A white fringe appears at the center with alternating bright spectra fringes. | Central White Fringe |
| What appears at the center when using white light in diffraction? | A white fringe with alternating bright spectra fringes. |
| Violet is closest to the center, and red is furthest in the diffraction pattern. | Violet and Red Fringes |
| Which colors are closest and furthest in the white light diffraction pattern? | Violet is closest, and red is furthest. |
| Always wear laser safety goggles when using lasers. | Laser Safety Goggles |
| What is a key safety precaution when using lasers? | Wear laser safety goggles. |
| Avoid shining lasers at reflective surfaces. | Reflective Surfaces |
| Why should lasers not be shone at reflective surfaces? | To avoid dangerous reflections. |
| Display a warning sign when using lasers. | Warning Signs |
| What precaution should be taken when using lasers in public spaces? | Display a warning sign. |
| Never shine the laser at a person. | Directing the Laser |
| Where should you never point a laser? | At a person. |
| Interference in sound waves can be demonstrated using two speakers connected to the same signal generator. | Sound Wave Interference |
| How can interference in sound waves be demonstrated? | By using two speakers connected to the same signal generator. |
| The intensity of the sound wave can be measured with a microphone to find maxima (like light fringes) and minima (like dark fringes). | Measuring Sound Wave Interference |
| How can you measure maxima and minima in sound wave interference? | Use a microphone to measure wave intensity and find maxima and minima. |
| Young's double slit experiment provided evidence for the wave nature of light through diffraction and interference. | Wave Nature of Light |
| How did Young's double slit experiment prove the wave nature of light? | By demonstrating diffraction and interference, which are wave properties. |
| Before Young's experiment, some believed light was made of particles, but the experiment disproved this theory. | Particle Theory of Light |
| What theory about light was disproved by Young's double slit experiment? | The theory that light was made of particles. |
| Scientific understanding changes over time based on experimental evidence gathered by the scientific community. | Changing Scientific Understanding |
| How does scientific knowledge change over time? | It evolves based on experimental evidence collected by the scientific community. |
