Chapter 11 - Conductors and Insulators - Grob's Basic Electronics 13th

A closed switch has a resistance of approximately: a. infinity. b. zero ohms. c. 1 MΩ. d. none of the above.

b

An open fuse has a resistance that approaches: a. infinity. b. zero ohms. c. 1 to 2 Ω. d. none of the above.

a

How many connecting terminals does an SPDT switch have? a. 2. b. 6. c. 3. d. 4.

c

The voltage drop across a closed switch equals: a. the applied voltage. b. zero volts. c. infinity. d. none of the above.

b

For round wire, as the gage numbers increase from 1 to 40: a. the diameter and circular area increase. b. the wire resistance decreases for a specific length and type. c. the diameter increases but the circular area remains constant. d. the diameter and circular area decrease.

d

The circular area of round wire doubles for: a. every 2 gage sizes. b. every 3 gage sizes. c. each successive gage size. d. every 10 gage sizes.

b

Which has more resistance, a 100-ft length of No. 12 gage copper wire or a 100-ft length of No. 12 gage aluminum wire? a. The 100-ft length of No. 12 gage aluminum wire. b. The 100-ft length of No. 12 gage copper wire. c. They both have exactly the same resistance. d. It cannot be determined.

a

In their pure form, all metals have a: a. negative temperature coefficient. b. temperature coefficient of zero. c. positive temperature coefficient. d. very high resistance.

c

The current rating of a switch corresponds to the maximum current the switch can safely handle when it is: a. open. b. either open or closed. c. closed. d. none of the above.

c

How much is the resistance of a 2000-ft length of No. 20 gage aluminum wire? a. less than 1 Ω. b. 20.35 Ω. c. 3.33 kΩ. d. 33.27 Ω.

d

How many completely isolated circuits can be controlled by a DPST switch? a. 1. b. 2. c. 3. d. 4.

b

Which of the following metals is the best conductor of electricity? a. steel. b. aluminum. c. silver. d. gold.

c

What is the area in circular mils (cmils) of a wire whose diameter, d, is 0.01 in.? a. 0.001 cmil. b. 10 cmil. c. 1 cmil. d. 100 cmil.

d

The term pole as it relates to switches is defined as: a. the number of completely isolated circuits that can be controlled by the switch. b. the number of closed contact positions that the switch has. c. the number of connecting terminals the switch has. d. none of the above.

a

The motion of ion charges in a liquid or gas is called: a. the corona effect. b. hole flow. c. superconductivity. d. ionization current.

d