Take a piece of cardboard and make a thin cut in it with a sharp razor blade, a razor blade carpet knife will do. look at a light source through the slit. you should see a series of dark lines (called interference fringes) appearing through your slit. repeat this experiment with two very closely spaced slits. could these fringes appear if light had only a particle nature? explain in terms of the wave property of light. 1. while sound is not an electromagnetic wave it does have energy like electromagnetic waves. many of us have performed the experiment in which sunlight is focused onto a paper on fire illustrating the energy in light. to see the energy of sound waves, hold a tissue in front of the speaker of a stereo system. shut the doors and windows so the tissue remains still. switch on the stereo and turn up the volume. does the tissue remain still? explain the results. 2. piece of paper with a magnifying glass.

nec chapter 5 contains

c. information on special occupancy areas

nec chapter 6 covers

a. special equipment

which of the following rules contain the words shall or shall not and must be adhered to?

b. mandatory rules

which of the following rules identify actions that are allowed but not required and typically cover options or alternative methods?

c. optional rules

which of the following serves as the introduction to the nec and provides an overview of the book?

a. nec article 90

organizations that test products for safety are

c. nrtls

the nec is published by the

a national fire protection association

the nec is divided into

b. 9 chapters

the nec provides informative annexes for

c. informational materials and examples

two terms from nec article 100 that trainees should become familiar with are

b. labeled and listed

explanation:

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.