DC Circuits Test 1 Intro-Ch. 2
The charge of one electron is ______ Coulomb.
.16 x 10^-18
Surface mount resistors have power have power ratings of 1/8 to ____ watt(s)
1/4
The unit of current is the:
Ampere
True or False: An open resistor measures zero ohms.
False
A short circuit can have:
excessive current
A battery:
produces a steady DC voltage
The fifth band in a precision resistor represents the:
tolerance
A neutral dielectric has 18.75 x 10^18 electrons removed. The dielectric now has a net charge of: Hint: 1 Coulomb=6.25 x 10^18
+3 Coulombs
12,000 watts is equal to ______kW
12kW
If an insulator is charged for 3 seconds by 5 amps of current, the charge accumulated will be: Hint: I=Q/T
15 Coulombs
A current of 2000 microamps also equals ________mA
2mA
A charge of 10 Coulombs moves past a given point in 2 seconds. The current flow is: Hint: I=Q/T
5 amperes
The descriptive unit of charge (Q) is the:
Coulomb
True or False: An electron flow rate of one coulomb per second is called a volt.
False
True or False: Resistors have a very limited shelf life.
False
True or False: The larger the American Standard Wire Gauge (AWG) number, the larger the wire diameter.
False
True or False: The most common resistor trouble is a short.
False
True or False: The resistance of a PTC thermistor increases as its operating temperature decreases.
False
True or False: Carbon film and metal film resistors have more precise resistance values than carbon composition resistors.
True
True or False: Four-band resistors under 10 ohms have a third stripe that is either gold or silver.
True
True or False: Insulators prevent current flow.
True
True or False: Rheostats and potentiometers are variable resistors.
True
True or False: The charge of an electron and proton are the same, but the polarity is opposite.
True
True or False: The physical size of a resistor determines its power handling capabilities.
True
True or False: The power rating of a carbon resistor is not affected by the ambient temperature.
True
True or False: The unit of potential difference is the volt.
True
True or False: There are 120 milliamps in 0.12 amps.
True
True or False: Thermistors are normally rated by the value of their resistance at a reference temperature, T of 25*C.
True
True or False: Voltage can exist without current.
True
True or False: When measuring resistance in a circuit, it is important to be sure there are no parallel paths across the resistor being measured.
True
True or False: When working with high-voltage circuits, work with only one hand at a time to prevent electrical shock.
True
Which statement is NOT true? a rheostat can be used as a potentiometer. a potentiometer can be used as a rheostat. a potentiometer is a three-terminal device. a rheostat is a two terminal device.
a rheostat can be used as a potentiometer
The basic building block of matter is the:
atom
Ball A is positively charged to some value. Ball B has twice the positive charged value of A. When the two balls are brought together, there will be a force of ________ because ball A is _______ with respect to ball B.
attraction, negative
A(n) ________ converts chemical energy into electrical energy.
battery
The movement of _____ is called current.
charge
Valence electrons of an atom determine the:
chemical and electrical stability
Gold is classified in electricity as a(n) _________.
conductor
Conventional current flow and electron current flow:
flow in opposite directions
The moving charges that provide current in metal conductors like copper wire are:
free electrons
An ion is an atom that has:
lost or gained one or more valence electrons
A generator produces electricity by converting ________ energy.
mechanical
The smallest unit into which a compound may be divided without altering the characteristics of the compound is a:
molecule
The third digit on a surface mount resistor is the _______ expressed as an exponent.
multiplier
Electrons flowing through an electronic circuit usually encounter opposition to their free movement. The opposition is measured in:
ohms
__________ designates the differences in charges between two points.
polarity
A resistor's physical size is an indicator of it's _______ rating, not its _______ value.
power, resistance
The resistance of a short piece of copper wire is:
practically zero
Chip resistors are also known as:
surface mount resistors
Electrons found in the outermost shell are called _______ electrons.
valence
The unit of electrical power is the:
watt
Energy is the ability to do __________.
work
An open circuit has:
zero current