Polarization

Light waves are transverse electromagnetic waves with the electric and magnetic field vectors oscillating perpendicular to the direction of 1) …(propagate). The atoms of a light source generally emit light waves that are 2) … (random) oriented and a beam of light has transverse field vectors in all 3) … (direct). Such light is said to be 4) … (polarize). Polarization refers to the5) … (prefer) orientation of the field vectors. If there is some 6) … (part) preferential orientation of the field vectors, the light is 7) … (part) polarized. If the vectors are in a single plane, the light is 8) … (line) polarized.

D. Choose the right words from the list to fill in the spaces:

White, incident, interference, parallel, red, light waves, sound waves, away

from, violet, toward, internal reflection, diffuse reflection, dispersion.

1. Rays reflected from relatively rough surfaces are not …; this is called diffuse reflection.

2. Because of … … in all directions, an ordinary object can be seen from many different angles.

3. The angle of refraction depends on the speed of light in the two media and on the … angle.

4. When light passes from one material into a second material where the index of refraction is less (say, from water into air), the light bends … the normal.

5. The ray bends … the normal when entering the water.

6. … light is electromagnetic radiation containing all wavelengths visible to the human eyes.

7. … light has a shorter wavelength than … light.

8. A diamond is said to have “fire” because of colourful …, in addition to having brilliance due to … …

9. We are well aware that … … bend around the corners while … … do not.

10. The colourful display seen in oil films and soap bubbles can be explained by …

E. Fill in the gaps with the verbs in brackets using the to-infinitive or the bare infinitive form

1. In working out lens problems we usually want … the image distance (know).

2. He saw the magnetic field … the beam of electrons downward in the discharge tube (deflect).

3. Diffraction can … rise to interference (give).

4. Polarizing sunglasses allow only the vertical component of the light … (pass).

5. Let’s … certain terms to explain the action of all waves in this figure (use).

6. You had better … polarizing sunglasses if you want to reduce the glare. (wear).

7. The extra cargo made the ship … (sink).

8. The Sun will cause the temperature … (rise).

9. He was made … the results of his experiment on the diagram (illustrate).

10. In the course of the upper-air observations with the help of the radiosond we saw the carrier balloon … (burst).

F. Put the verbs in brackets into the correct infinitive or the -ing form

1. I can’t help … (wonder) how Andy managers to afford … (run) such an expensive car.

2. I avoid … (travel) in the rush-hour if I can.

3. If you don’t stop … (waste) your time and at least try … (do) something, the boss will be furious.

4. I’m looking forward to … (see) you again soon.

5. I meant … (get up) earlier but I forgot to set my alarm clock.

6. If you can’t sleep properly, try … (walk) before you go to bed.

7. I can’t get used to … (get up) early.

8. You’ll never regret … (do) a kind action.

9. As teenagers we used to … (understand) each other very well.

10. It’s no use … (complain). They won’t do anything about it.

G. Choose the correct answer

1. The world … the same since the first atomic bomb was exploded above the New Mexico desert.

a) was never; b) has never been; c) had never been.

2. The objects in our environment … of matter.

a) are composed; b) were composed; c) will be composed.

3. The science of chemistry … with the composition, structure, properties of matter and the transformation that this matter undergoes.

a) dealt; b) is dealing; c) deals.

4. By the time the scientific method was born in the sixteenth century, much … about the properties of matter.

a) was discovered; b) has been discovered; c) had been discovered.

5. Einstein’s equation which related mass to energy … since 1905.

a) is known; b) has been known; c) was known.

6. Our modern listing of elements … to 109 with more expected.

a) has grown; b) has been; grown c) grew.

7. Alchemy… a mixture of magic and experimentation.

a) was; b) has been; c) had been.

8. Our knowledge of the universe …

a) grows; b) grew; c) is growing.

9. Since Berzelius’ time most elements … by the first one or two letters of the English name (C for carbon, O for oxygen, H for hydrogen).

a) have symbolized; b) were symbolized; c) have been symbolized.

10. In the very earliest of civilization nine elements …: gold, silver, lead, copper, tin, iron, carbon, sulfur and mercury.

a) had been isolated; b) were isolated; c) are isolated.

H. Translate the following text: