ANSWERS TO QUESTIONS Q1. THROUGH Q65.
A2.A substance which cannot be reduced to a simpler substance by chemical means.
A3.A substance consisting of two or more elements.
A4.A compound is a chemical combination of elements that cannot be separated by physical means. A mixture is a physical combination of elements and compounds that are not chemically combined.
A5.A chemical combination of two or more atoms.
A6.Electrons-negative, protons-positive, and neutrons-neutral.
A8.Invisible light photons (ultraviolet) bombard the phosphor atom in the light tube. The phosphor atoms emit visible light photons.
A9.The number of electrons in the outer shell.
A10.An atom with more or less than its normal number of electrons.
A11.The number of valence electrons.
A12.Through the accumulation of excess electrons.
A15.Like charges repel, and unlike charges attract with a force directly proportional to the product of their charges and inversely proportional to the square of the distance between them.
A16.The space between and around charged bodies.
A17.Leaving positive, entering negative.
A18.Motors, generators, speakers, computers, televisions, tape recorders, and many others.
A19.Those materials that are attracted by magnets and have the ability to become magnetized.
A20.The relative ease with which they are magnetized.
A21.A material that exhibits low reluctance and high permeability, such as iron or soft steel.
A22.The ability of a material to retain magnetism.
A23.They are very similar; like charges repel, unlike charges attract, like poles repel unlike poles attract.
A24.To the magnetic north pole.
A25.South pole at the right, north pole at the left.
A26.The domain theory is based upon the electron spin principle; Weber's theory uses the concept of tiny molecular magnets.
A27.To enable you to "see" the magnetic field.
A28.No specific pattern, sawdust is a nonmagnetic material.
A29.An imaginary line used to illustrate magnetic effects.
A30.Electrostatic lines of force do not form closed loops.
A31.By shielding or surrounding the instrument with a soft iron case, called a magnetic shield or screen.
A32.In pairs, with opposite poles together to provide a complete path for magnetic flux.
A33.The ability to do work.
A36.Difference of potential.
A38.(a) 250 kV, (b) 25 V, (c) 1 mV.
A39.A voltage source.
A40.Friction, pressure, heat, light, chemical action, and magnetism.
A45.Electron theory assumes that electron flow is from negative to positive.
A46.The speed of light (186,000 miles per second, 300,000,000 meters per second).
A47.Current increases as voltage increases.
A50.When the need for conductivity is great enough to justify the additional expense.
A53.Zero temperature coefficient.
A54.The mho (), siemans.
A55.They are reciprocals of each other.
A57.Its ability to dissipate heat.
A58.1. Change value with age.
A59.The wirewound resistor.
A60.The rheostat may have two connections, one fixed and one moveable; the potentiometer always has three connections, one moveable and two fixed.
A62.The bands are green, black, black, and gold.
A63.470,000 ohms (470 kilohms).
A64.The resistor's chance of failure is 0.001 percent for 1000 hours of operation.
A65.6,800,000 ohms (6.8 megohms), with 5% tolerance, and a 1% reliability level.