Dale Crane’s Oral And Practical Exam Questions
And Answers Verified 100% Correct
What instrument is used to measure electrical resistance? - ANSWER- An ohmmeter
How can you tell the resistance of a composition resistor? - ANSWER- -By a series of
colored bands around one end of the resistor
-The resistor color code is made up of a group of colors, numbers, and tolerance values.
Each color is represented by a number, and in most cases, by a tolerance value. When
the color code is used with the end-to-center band marking system, the resistor is
normally marked with bands of color at one end of the resistor. The body or base color
of the resistor has nothing to do with the color code, and in no way indicates a
resistance value. To prevent confusion, this body will never be the same color as any of
the bands indicating resistance value. (FAA-H-8083-30, Ch. 10)
What is meant by continuity in an electrical circuit? - ANSWER- -The circuit is
continuous (or complete) when electrons can flow from one terminal of power source to
the other
-Continuity — the state of being continuous, unin- terrupted or connected together; the
opposite of a circuit that is not broken or does not have an open. (FAA-H-8083-30, Ch.
10)
What instrument is used to measure continuity in an electrical circuit? - ANSWER- An
ohmmeter
When measuring resistance of a component with an ohmmeter, should the circuit be
energized? - ANSWER- No, there should be no power on the circuit
What three things must an electric circuit contain? - ANSWER- A source of electrical
energy, a load to use, and conductors to join the source and the load
What are the types if DC circuits with regard to the placement of various circuit
components? - ANSWER- -Series, parallel, and series-parallel
-The series circuit is the most basic electrical circuit and provides a good introduction to
basic circuit analysis. A simple circuit with nothing more than a voltage source or
battery, a conductor, and a resistor. This is classified as a series circuit because the
components are connected end-to-end, so that the same current flows through each
component equally. There is only one path for the current to take and the battery and
resistor are in series with each other; (FAA-H-8083-30, Ch. 10)
, -For resistors in a series configuration, the total resistance of the circuit is equal to the
sum of the individual resistors. The basic formula is:
R(T) = R(1) + R(2) + R(3) + .........R(N)
-In a series circuit, the current cannot be different at different points within the circuit.
The current through a series circuit will always be the same through each element and
at any point
-A law of basic importance to the analysis of an electrical circuit is Kirchhoff's voltage
law. This law simply states that the algebraic sum of all voltages around a closed path
or loop is zero. Another way of saying it: The sum of all the voltage drops equals the
total source voltage
-A circuit in which two of more electrical resistances or loads are connected across the
same voltage source is called a parallel circuit. The primary difference between the
series circuit and the parallel circuit is that more than one path is provided for the
current in the parallel circuit. Each of these parallel paths is called a branch. The
minimum requirements for a parallel circuit are the following: (FAA-H-8083-30, Ch. 10)
-A power source, conductors, a resistance or load for each current path, two or more
paths for current flow
-The voltage across any branch is equal to the voltage across all of the other branches.
-The parallel circuit consists of two or more resistors connected in such a way as to
allow current ow to pass through all of the resistors at once. This eliminates the need for
current to pass one resistor before passing through the next. When resistors are
connected in par- allel, the total resistance of the circuit decreases. The total resistance
of a parallel combination is always less than the value of the smallest resistor in the
circuit. In the series circuit, the current has to pass through the resistors one at a time.
This gave a resistance to the current equal the sum of all the resistors. In the parallel
circuit, the current has several resistors that it can pass through, actually reducing the
total resistance of the circuit in relation to any one resistor value.
-The formula for the total parallel resistance is as follows:
1/R(t) = 1/R(1) + 1/R(2) + 1/R(3) ... + 1/R(n)
-If the reciprocal of both sides is taken, then the general formula for the total parallel
resistance is:
R(t) = 1/((1/R(1)) + (1/R(2)) + (1/R(3)) ... (1/R(n)))
-The amount of current passing through each resistor will vary according to its
individual resistance. The total current of the circuit will then be the sum of the current in
all branches. It can be determined by inspec- tion that the total current will be greater
than that of any given branch.
-Kirchhoff's current law can be stated as: The sum of the currents into a junction or
node is equal to the sum of the currents owing out of that same junction or node. A
junction can be de ned as a point in the circuit where two or more circuit paths come
together. In the case of the parallel circuit, it is the point in the circuit where the
individual branches join.
General formula I(T) = I(1) + I(2) + I(3)
,-Most of the circuits that the technician will encounter will not be a simple series or
parallel circuit. Circuits are usually a combination of both, known as series-par- allel
circuits, which are groups consisting of resistors in parallel and in series.
What is the law that describes the relationship in an electrical circuit of voltage, current
and resistance? - ANSWER- -Ohm's Law
-The two fundamental properties of current and voltage are related by a third property
known as resistance. In any electrical circuit, when voltage is applied to it, a current will
result. The resistance of the conductor will determine the amount of current that ows
under the given voltage. In most cases, the greater the cir- cuit resistance, the less the
current. If the resistance is reduced, then the current will increase. This relation is linear
in nature and is known as Ohm's law. (FAA-H-8083-30, Ch. 10)
What is the basic equation of Ohm's law? - ANSWER- E = I x R
where E = Voltage, I = Current, and R = Resistance
What formula is used to find current when voltage and resistance are known? -
ANSWER- I = E / R
What formula is used to find resistance when voltage and current are known? -
ANSWER- R = E / I
What happens to the current in a DC circuit if the voltage is increased but the resistance
remains the same? - ANSWER- -It increases
-By having a linearly proportional characteristic, it is meant that if one unit in the
relationship increases or decreases by a certain percentage, the other variables in the
relationship will increase or decrease by the same percentage. An example would be if
the voltage across a resistor is doubled, then the current through the resistor doubles. It
should be added that this relationship is true only if the resistance in the circuit remains
constant. For it can be seen that if the resistance changes, current also changes.
(FAAH-8083-30, Ch. 10)
What happens to the current in a conductor if the length of conductor is doubled with all
other parameters unchanged? - ANSWER- -It would decrease one half
-The resistance of a metallic conductor is directly proportional to its length. The longer
the length of a given size of wire, the greater the resistance. If 1 volt of electrical
pressure is applied across the two ends of the conductor that is 1 foot in length and the
resistance to the movement of free electrons is assumed to be 1 ohm, the current flow
is limited to 1 ampere. If the same size conductor is doubled in length, the same
electrons set in motion by the 1 volt applied now find twice the resistance; consequently,
the current flow will be reduced by one-half. (FAA-H-8083-30, Ch. 10)
What is the voltage across each resistor connected in parallel across a 12-volt battery?
- ANSWER- -12 volts
-The voltage across any branch is equal to the voltage across all of the other branches.
, (FAA-H-8083-30, Ch. 10)
How much current flows through each of the three resistors connected in series if the
total current is 3 amps? - ANSWER- -3 amps
-In a series circuit, the current cannot be different at different points within the circuit.
The current through a series circuit will always be the same through each element and
at any point. (FAA-H-8083-30, Ch. 10)
What is the total resistance of three 12-ohm resistors connected in series? - ANSWER-
-36 ohms
-For resistors in a series con guration, the total resistance of the circuit is equal to the
sum of the individual resistors. The basic formula is: (FAA-H-8083-30, Ch. 10) R(T)
= R(1) + R(2) + R(3) + .........R(n)
What is the total resistance of three 12-ohm resistors in parallel? - ANSWER- -4 ohms -
When resistors are connected in par- allel, the total resistance of the circuit decreases.
The total resistance of a parallel combination is always less than the value of the
smallest resistor in the circuit. In the series circuit, the current has to pass through the
resistors one at a time. This gave a resistance to the current equal the sum of all the
resistors. In the parallel circuit, the current has several resistors that it can pass through,
actually reducing the total resistance of the circuit in relation to any one resistor value.
(FAA-H-8083-30, Ch. 10)
-The formula for the total parallel resistance is as follows:
1/R(t) = 1/R(1) + 1/R(2) + 1/R(3) ... + 1/R(n)
-If the reciprocal of both sides is taken, then the general formula for the total parallel
resistance is:
R(t) = 1/((1/R(1)) + (1/R(2)) + (1/R(3)) ... (1/R(n)))
What is meant by the capacity rating of a lead-acid battery? - ANSWER- -The number
of hours a battery can supply a given current flow
-The most common battery rating is the amp-hour rating. This is a unit of measurement
for battery capacity. It is determined by multiplying a current ow in amperes by the time
in hours that the battery is being discharged. A battery with a capacity of 1 amp-hour
should be able to continuously supply a current of 1 amp to a load for exactly 1 hour, or
2 amps for 1/2 hour, or 1/3 amp for 3 hours, etc., before becoming completely
discharged. Actually, the ampere-hour output of a particular battery depends on the rate
at which it is discharged. Heavy discharge current heats the battery and decreases its ef
ciency and total ampere-hour output. For airplane batteries, a period of 5 hours has
been established as the discharge time in rating battery capacity. However, this time of
5 hours is only a basis for rating and does not necessarily mean the length of time
during which the battery is expected to furnish current. Under actual service conditions,
the battery can be completely discharged within a few minutes, or it may never be
discharged if the generator provides sufficient charge. (FAA-H-8083-30, Ch. 10)
And Answers Verified 100% Correct
What instrument is used to measure electrical resistance? - ANSWER- An ohmmeter
How can you tell the resistance of a composition resistor? - ANSWER- -By a series of
colored bands around one end of the resistor
-The resistor color code is made up of a group of colors, numbers, and tolerance values.
Each color is represented by a number, and in most cases, by a tolerance value. When
the color code is used with the end-to-center band marking system, the resistor is
normally marked with bands of color at one end of the resistor. The body or base color
of the resistor has nothing to do with the color code, and in no way indicates a
resistance value. To prevent confusion, this body will never be the same color as any of
the bands indicating resistance value. (FAA-H-8083-30, Ch. 10)
What is meant by continuity in an electrical circuit? - ANSWER- -The circuit is
continuous (or complete) when electrons can flow from one terminal of power source to
the other
-Continuity — the state of being continuous, unin- terrupted or connected together; the
opposite of a circuit that is not broken or does not have an open. (FAA-H-8083-30, Ch.
10)
What instrument is used to measure continuity in an electrical circuit? - ANSWER- An
ohmmeter
When measuring resistance of a component with an ohmmeter, should the circuit be
energized? - ANSWER- No, there should be no power on the circuit
What three things must an electric circuit contain? - ANSWER- A source of electrical
energy, a load to use, and conductors to join the source and the load
What are the types if DC circuits with regard to the placement of various circuit
components? - ANSWER- -Series, parallel, and series-parallel
-The series circuit is the most basic electrical circuit and provides a good introduction to
basic circuit analysis. A simple circuit with nothing more than a voltage source or
battery, a conductor, and a resistor. This is classified as a series circuit because the
components are connected end-to-end, so that the same current flows through each
component equally. There is only one path for the current to take and the battery and
resistor are in series with each other; (FAA-H-8083-30, Ch. 10)
, -For resistors in a series configuration, the total resistance of the circuit is equal to the
sum of the individual resistors. The basic formula is:
R(T) = R(1) + R(2) + R(3) + .........R(N)
-In a series circuit, the current cannot be different at different points within the circuit.
The current through a series circuit will always be the same through each element and
at any point
-A law of basic importance to the analysis of an electrical circuit is Kirchhoff's voltage
law. This law simply states that the algebraic sum of all voltages around a closed path
or loop is zero. Another way of saying it: The sum of all the voltage drops equals the
total source voltage
-A circuit in which two of more electrical resistances or loads are connected across the
same voltage source is called a parallel circuit. The primary difference between the
series circuit and the parallel circuit is that more than one path is provided for the
current in the parallel circuit. Each of these parallel paths is called a branch. The
minimum requirements for a parallel circuit are the following: (FAA-H-8083-30, Ch. 10)
-A power source, conductors, a resistance or load for each current path, two or more
paths for current flow
-The voltage across any branch is equal to the voltage across all of the other branches.
-The parallel circuit consists of two or more resistors connected in such a way as to
allow current ow to pass through all of the resistors at once. This eliminates the need for
current to pass one resistor before passing through the next. When resistors are
connected in par- allel, the total resistance of the circuit decreases. The total resistance
of a parallel combination is always less than the value of the smallest resistor in the
circuit. In the series circuit, the current has to pass through the resistors one at a time.
This gave a resistance to the current equal the sum of all the resistors. In the parallel
circuit, the current has several resistors that it can pass through, actually reducing the
total resistance of the circuit in relation to any one resistor value.
-The formula for the total parallel resistance is as follows:
1/R(t) = 1/R(1) + 1/R(2) + 1/R(3) ... + 1/R(n)
-If the reciprocal of both sides is taken, then the general formula for the total parallel
resistance is:
R(t) = 1/((1/R(1)) + (1/R(2)) + (1/R(3)) ... (1/R(n)))
-The amount of current passing through each resistor will vary according to its
individual resistance. The total current of the circuit will then be the sum of the current in
all branches. It can be determined by inspec- tion that the total current will be greater
than that of any given branch.
-Kirchhoff's current law can be stated as: The sum of the currents into a junction or
node is equal to the sum of the currents owing out of that same junction or node. A
junction can be de ned as a point in the circuit where two or more circuit paths come
together. In the case of the parallel circuit, it is the point in the circuit where the
individual branches join.
General formula I(T) = I(1) + I(2) + I(3)
,-Most of the circuits that the technician will encounter will not be a simple series or
parallel circuit. Circuits are usually a combination of both, known as series-par- allel
circuits, which are groups consisting of resistors in parallel and in series.
What is the law that describes the relationship in an electrical circuit of voltage, current
and resistance? - ANSWER- -Ohm's Law
-The two fundamental properties of current and voltage are related by a third property
known as resistance. In any electrical circuit, when voltage is applied to it, a current will
result. The resistance of the conductor will determine the amount of current that ows
under the given voltage. In most cases, the greater the cir- cuit resistance, the less the
current. If the resistance is reduced, then the current will increase. This relation is linear
in nature and is known as Ohm's law. (FAA-H-8083-30, Ch. 10)
What is the basic equation of Ohm's law? - ANSWER- E = I x R
where E = Voltage, I = Current, and R = Resistance
What formula is used to find current when voltage and resistance are known? -
ANSWER- I = E / R
What formula is used to find resistance when voltage and current are known? -
ANSWER- R = E / I
What happens to the current in a DC circuit if the voltage is increased but the resistance
remains the same? - ANSWER- -It increases
-By having a linearly proportional characteristic, it is meant that if one unit in the
relationship increases or decreases by a certain percentage, the other variables in the
relationship will increase or decrease by the same percentage. An example would be if
the voltage across a resistor is doubled, then the current through the resistor doubles. It
should be added that this relationship is true only if the resistance in the circuit remains
constant. For it can be seen that if the resistance changes, current also changes.
(FAAH-8083-30, Ch. 10)
What happens to the current in a conductor if the length of conductor is doubled with all
other parameters unchanged? - ANSWER- -It would decrease one half
-The resistance of a metallic conductor is directly proportional to its length. The longer
the length of a given size of wire, the greater the resistance. If 1 volt of electrical
pressure is applied across the two ends of the conductor that is 1 foot in length and the
resistance to the movement of free electrons is assumed to be 1 ohm, the current flow
is limited to 1 ampere. If the same size conductor is doubled in length, the same
electrons set in motion by the 1 volt applied now find twice the resistance; consequently,
the current flow will be reduced by one-half. (FAA-H-8083-30, Ch. 10)
What is the voltage across each resistor connected in parallel across a 12-volt battery?
- ANSWER- -12 volts
-The voltage across any branch is equal to the voltage across all of the other branches.
, (FAA-H-8083-30, Ch. 10)
How much current flows through each of the three resistors connected in series if the
total current is 3 amps? - ANSWER- -3 amps
-In a series circuit, the current cannot be different at different points within the circuit.
The current through a series circuit will always be the same through each element and
at any point. (FAA-H-8083-30, Ch. 10)
What is the total resistance of three 12-ohm resistors connected in series? - ANSWER-
-36 ohms
-For resistors in a series con guration, the total resistance of the circuit is equal to the
sum of the individual resistors. The basic formula is: (FAA-H-8083-30, Ch. 10) R(T)
= R(1) + R(2) + R(3) + .........R(n)
What is the total resistance of three 12-ohm resistors in parallel? - ANSWER- -4 ohms -
When resistors are connected in par- allel, the total resistance of the circuit decreases.
The total resistance of a parallel combination is always less than the value of the
smallest resistor in the circuit. In the series circuit, the current has to pass through the
resistors one at a time. This gave a resistance to the current equal the sum of all the
resistors. In the parallel circuit, the current has several resistors that it can pass through,
actually reducing the total resistance of the circuit in relation to any one resistor value.
(FAA-H-8083-30, Ch. 10)
-The formula for the total parallel resistance is as follows:
1/R(t) = 1/R(1) + 1/R(2) + 1/R(3) ... + 1/R(n)
-If the reciprocal of both sides is taken, then the general formula for the total parallel
resistance is:
R(t) = 1/((1/R(1)) + (1/R(2)) + (1/R(3)) ... (1/R(n)))
What is meant by the capacity rating of a lead-acid battery? - ANSWER- -The number
of hours a battery can supply a given current flow
-The most common battery rating is the amp-hour rating. This is a unit of measurement
for battery capacity. It is determined by multiplying a current ow in amperes by the time
in hours that the battery is being discharged. A battery with a capacity of 1 amp-hour
should be able to continuously supply a current of 1 amp to a load for exactly 1 hour, or
2 amps for 1/2 hour, or 1/3 amp for 3 hours, etc., before becoming completely
discharged. Actually, the ampere-hour output of a particular battery depends on the rate
at which it is discharged. Heavy discharge current heats the battery and decreases its ef
ciency and total ampere-hour output. For airplane batteries, a period of 5 hours has
been established as the discharge time in rating battery capacity. However, this time of
5 hours is only a basis for rating and does not necessarily mean the length of time
during which the battery is expected to furnish current. Under actual service conditions,
the battery can be completely discharged within a few minutes, or it may never be
discharged if the generator provides sufficient charge. (FAA-H-8083-30, Ch. 10)
