review DC theory Flashcards
The ? is one of the three main parts of an atom.
proton
The proton and electron combine to form the atom’s nucleus.
false
Current is defined as the flow of ? through a material.
electron
In calculations, current is represented by the letter ?
I
The electron has an electrical charge with a(n) ? polarity.
negative
Semiconductors have ? electrons in the valence shell.
4
A(n) ? is a material whose electrons can be moved with relative ease.
conductor
A(n) ? is a material whose electrons strongly oppose movement.
insulator
Like charges attract each other and unlike charges repel each other.
false
Any current-carrying conductor will create a(n) ? field.
magnetic
The primary source of electrical power is ?
magnetism
Ohm’s law states that one volt will push one ampere through one ohm of resistance.
true
A unit of electrical power is the ? and is represented in equations as the letter P.
watt
One horsepower is equal to approximately 746 ?
watts
Which of the following formulas is the correct expression of Ohm’s Law for power?
p = e*I
The heat produced by the current flowing through the resistance in a circuit is called ? losses.
l^2R
Electrical energy use is measured in ampere-hours which involves how much power is used with respect to time.
false
When resistors are connected in series, their values are ? to determine total resistance.
added
RT = R1 + R2 +…+ RN is the formula for determining the total resistance in a ? circuit.
series
What opposes current flow in an electrical circuit?
resistance
If the voltage in a given circuit is increased, the current will increase; but if the resistance is increased, then the current will decrease.
true
In a circuit, current is directly proportional to voltage and inversely proportional to resistance.
true
Which of the following is the correct formula for determining the total current in a circuit?
I = e/r
An increase in the total resistance of a series circuit will cause a(n) ? in the current of that circuit.
decrease
In series-opposing power sources, the power sources are connected so their polarities are in the same direction.
false
The greater the voltage across a fixed resistor, the greater the ? through that resistor.
current
As the current flows through each component in a series circuit, it will ?
remain the same
In a series circuit, the total voltage source is equal to the algebraic ? of the individual voltage sources.
sum
? is a potential difference in electron charges.
voltage
Adding additional resistors in parallel with those resistors already existing in a parallel circuit will always decrease the total resistance of the circuit.
true
Which of the following is the product-sum formula for determining total resistance in parallel circuits containing two unequal resistances?
r = r1r2/r1+r2
Branch currents in a parallel circuit are always less than the total current of the circuit.
true
Adding parallel loads to a circuit will increase the total circuit resistance and decrease the total circuit current.
true
The ? method is used to determine the total power in a parallel circuit when the power is determined from the total current, total resistance, and source voltage.
direct
