2167810
| Question | Answer |
| G.1.1 Outline the nature of electromagnetic (EM) waves | EM Waves are: (1) produced b/c of the acceleration of motion of electric charges; (2) all travel at the same speed in a vacuum (velocity of light) (3) carry momentum and energy |
| G.1.3 Describe what is meant by the dispersion of EM Waves. | Dispersion --> the separation of white light into its component colours (ROYGIBV) |
| G.1.4 Describe the dispersion of EM waves in terms of the dependence of refractive index on wavelength. | Refractive Index = ratio of speed of light in a vacuum to the speed of light in a medium. - Frequency of light remains constant as light passes through a medium. - EM waves "bend" differently as waves pas through a medium. - ∴ Longer wavelength EM waves bend less; shorter wavelength EM waves bend more. - Different colours emitted b/c of different index of refraction |
| G.1.5 Distinguish b/n the transmission, absorption & scattering (TAS) of radiation. | - Transmission (Emitted) --> same source providing radiation; - Absorption --> absorbed by an object w/o transmission (not letting it out) - Scattering --> the deflection of EM radiation from its original path due to its collisions w/ particles in a medium |
| Bonus Question! Why is the sky blue? | The sky 'appears' blue b/c certain molecules in the air scatter blue light MORE than red, orange or yellow light. When we look t/w the sun at sunset, we see red and orange colours b/c the blue light has been scattered out & is away from the line of sight. |
| G.1.6 Discuss an example of transmission, absorption and scattering of EM waves. | (1) Greenhouse Effect --> Greenhouse gases will TAS EM radiation. (2) Creation of the rainbow |
| G.1.7 Explain the terms Monochromatic and Coherent. | - Monochromatic --> Light or an EM wave consisting of only ONE wavelength. (λ) - Coherent --> Light or an EM wave w/ a constant phase difference (p.d.) --> so all EM waves are in phase |
| G.1.8 Identify laser light as a source of coherent light. | Laser light is a source of monochromatic and coherent light. |
| G.1.9 Outline the mechanism for the production of laser light (population inversion). | (1) LASER (Light Amplified by Stimulated Emission of Radiation)'s power source is to provide energy that excites the atoms in the light-amplifying substance to become excited. (2) Absorbs non-coherent radiation from a power source. Photons emitted from the electrons in the metastable all in phase (3) Atoms are excited to higher states w/ high voltage, drop down to lower energy state, then intermediate metastable in which electrons get 'stuck'. (4) Eventually, more electrons found in metastable state than ground state. Stay longer in the m.stable e.level. "Lasing" begins. |
| G.1.10 Outline an application of the use of a laser. | - Surgical tool for precision cuts or destruction of "bad" tissue - Reading a CD through reflection and interference |
| G.2.1 Define PRINCIPLE AXIS | The line that passes through the centre of curvature and centre of the refracting surface (lens). |
| G.2.1 Define FOCAL POINT | Point at which rays parallel to the principle axis pass through after refracting through the lens |
Want to create your own Flashcards for free with GoConqr? Learn more.