Make sure you have understood everything in this section (Lessons C1, C2 and C3).
Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.
This is also a good time to visit your Section 1 Checklist to make sure you have completed all the recommended learning activities.

Unit C Section 1 Self-Check

Instructions


Complete the following 6 steps. Don't skip steps – if you do them in order, you will confirm your understanding of this section and create a study bank for the future.

  1. DOWNLOAD the self-check quiz by clicking here.

  2. ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review the lessons of this section if you need to. Save your quiz when you are done.

  3. COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.

  4. REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.

  5. SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.

  6. CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum, or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!

Be a Self-Check

Superhero!



Self-Check Quiz Answers

Click each of the suggested answers below, and carefully compare your answers to the suggested answers.

If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.

Many modern technologies and optical devices use light to operate. For example:

  • Lasers are used in medical surgery procedures, to avoid physical cuts with a surgical knife in the body.
  • Lasers are used in barcode scanners to quickly find the price of an item and track what products sell in a store.
  • Cameras are used to capture and send images for communication.
  • Fibre optic cables are used to quickly send messages around the world by internet and telephone.
Dental lasers best demonstrate that light is a form of energy. The energy in laser light is transformed into heat energy, which removes decaying tooth material in a cavity.
A reflected light ray from a surface always has the same angle as the incoming ray of light. The incoming light angle was 60 degrees, so the reflected ray of light will also have an angle of 60 degrees.
Light has a speed of 300 000 000 meters per second (or 300 000 km per second). However, Alpha Centauri is so far away that it takes 4 years for the light leaving the star to reach Earth. We calculate this using the relationship:

Time = Distance âž— Speed
Time = 40 000 000 000 000 km âž— 300 000 km per second
Time  = 133 333 333 seconds, which is the same as 4.3 years.
Lenses bend light, which produces an image of an original object. Particular combinations of lenses can produce a magnified image, like in a telescope or microscope.