General A&P General questions
What is the total capacitance of a certain circuit containing three capacitors with capacitances of .25 microfarads, .03 microfarads, and .12 microfarads respectively?
.4 microfarads
A lead acid battery with 12 cells connected in series (no load voltage= 2.1 volts per cell) furnishes 10 amperes to a load of 2 ohms resistance. The internal resistance of the battery in this instance is
0.52 ohm
If 3 resistors 3 ohms, 5 ohms, and 22 ohms are connected in series in a 28 volt circuit, how much current will flow through the 3 ohm resistor?
0.93 ampere
A 12 volt electric motor has 1,000 watts input and 1 HP output. Maintaining the same efficiency, how much input power will a 24 volt, 1 HP electric motor require?
1,000 watts
A circuit has an applied voltage of 30 volts and a lad consisting of a 10 ohm resistor in series with a 20 ohm resistor. What is the voltage drop across the 10 ohm resistor?
10 volts
.002 KV equals
2.0 volts
A 24 volt source is required to furnish 48 watts to a parallel circuit consisting of 2 resistors of equal value. What is the value of each resistor?
24 ohms
A 24 volt source is required to furnish 48 watts to a parallel circuit consisting of 4 resistors of equal value. What is the voltage drop across each resistor?
24 volts
In a parallel circuit with 4 6 ohm resistors across a 24 volt battery, what is the total voltage across resistor 3 in the circuit?
24 volts
How many amperes will a 28 volt generator be required to supply to a circuit containing 5 lamps in parallel, 3 of which have a resistance of 6 ohms each and 2 of which have a resistance of 5 ohms each?
25.23 amperes
What is the operating resistance of a 30 watt light bulb designed for a 28 volt system?
26 ohms
A 48 volt source is required to furnish 192 watts to a parallel circuit consisting of 3 resistors of equal value. What is the value of each resistor?
36 ohms
How much power must a 24 volt generator furnish to a system which contains the following loads? 1 motor 1/5 HP 3 lights 20 watts ea Heating element 5 amp Anticollision light 3 amp
450 watts
In a parallel circuit with 3 6 ohm resistors across a 12 volt battery, what is the total current (It) value in the circuit?
6 amps
A 1 HP, 24 volt DC electric motor that is 80 percent efficient requires 932.5 watts. How much power will a 1 HP, 12 volt DC electric motor that is 75 percent efficient require?
994.6 watts
Which requires the most electrical power? A 1/5 HP 24 volt motor which is 75 percent efficient 4 30 watt lamps arranged in a 12 volt parallel circuit A 24 volt anticollision light circuit consisting of 2 light assemblies which require 3 amperes each during operation
A 1/5 HP 24 volt motor which is 75 percent efficient
If electrolyte from a lead-acid battery is spilled in the battery compartment, which procedure should be followed? Apply boric acid solution to the affected area followed by a water rise. Rinse the affected area thoroughly with clean water. Apply sodium bicarbonate solution to the affected area followed by a water rinse
Apply sodium bicarbonate solution to the affected area followed by a water rinse
Which is/are true? A detail drawing is a description of a single part An assembly drawing is a description of an object made up of two or more parts
BOTH
Which of the following statements is/are generally true regarding the charging of several aircraft batteries together? Batteries of different voltages (but similar capacities) can be connected in series with each other across the charger and charged using the constant current method Batteries of different ampere-hour capacity and same voltage can be connected in parallel with each other across the charger and charged using the constant voltage method. Batteries of the same voltage and same ampere-hour capacity must be connected in series with each other across the charger and charged using constant current method
Batteries of different voltages (but similar capacities) can be connected in series with each other across the charger and charged using the constant current method AND Batteries of different ampere-hour capacity and same voltage can be connected in parallel with each other across the charger and charged using the constant voltage method.
How can the state-of-charge of a nickel-cadmium battery be determined?
By a measured discharge
What material symbol is frequently used in drawings to represent all metals?
Cast iron
What is the likely result of service and charging nickel-cadmium and lead acid batteries together in the same service area?
Contamination of both batteries
What is the basic unit of electrical quantity?
Coulomb
Which of the following will cause the resistance of a conductor to decrease? Decrease the length or the cross sectional area Decrease the length or increase the cross sectional area Increase the length or decrease the cross sectional area
Decrease the length and increase the cross sectional area
What is the class of working drawing that is the description/depiction of a single part?
Detail drawing
Which of the following are commonly used as rectifiers in electrical circuits? Anodes Cathodes Diodes
Diodes
What may result if water is added to a nickel-cadmium battery when it is not fully charged?
Excessive spewing is likely to occur during the charging cycle
What is used to indicate that a surface must be machine finished?
Finished marks
Which condition is an indication of improperly torqued cell link connections of a nickel-cadmium battery? Light spewing at the cell caps Toxic and corrosive deposits of potassium carbonate crystals Heat or burn marks on the hardware
Heat or burn marks on the hardware
A line used to show an edge which is not visible is a phantom line hidden line break line
Hidden line
Which is correct in reference to electrical resistance? 2 electrical devices will have the same combined resistance if they are connected in series as they will have if connected in parallel If 1 of 3 bulbs in a parallel circuit is removed, the total resistance of the circuit will become greater An electrical device that has a high resistance will use more power than one with a low resistance with the same applied voltage
If 1 of 3 bulbs in a parallel circuit is removed, the total resistance of the circuit will become greater
An increase in which of the following factors will cause an increase in the inductive reactance of a circuit? Inductance and frequency Resistance and voltage Resistance and capacitive reactance
Inductance and frequency
What is the opposition to the flow of AC produced by a magnetif field with generated back voltage (EMF) called?
Inductive reactance
Through which material will magnetic lines of force pass the most easily? Iron Copper Aluminum
Iron
Which of the following best describes the contributing factors to thermal runaway in a nickel-cadmium battery installed on an aircraft?
Low internal resistance intensified by high cell temperatures and a high current discharge/charge rate in a constant potential (voltage) charging system
What type of line is normally used in a mechanical drawing or blueprint to represent an edge or object not visible to the viewer?
Medium weight dashed line
Which term means .001 ampere?
Milliampere
Which is/are true? Sketches are usually made with the aid of drafting instruments Sketches are usually more complicated to make when using graph paper
Neither are true
Which statement is true regarding an orthographic projection? There are always t least 2 views It could have as many as 8 views One-view, two-view, and three view drawings are the most common
One-view, two-view, and three view drawings are the most common
Which is/are true? diagrams indicate the location of individual components in the aircraft Schematic diagrams indicate the location of components with respect to each other within the system
Only No. 2 is true
Which is/are true? According to 14 CFR Part 91, repairs to an aircraft skin, should have a detailed dimensional sketch included in the permanent records On occasion, a mechanic may need to make a simple sketch of a proposed repair to an aircraft, a new design, or a modification.
Only No. 2 is true
In a sectional view drawing, what sections illustrate particular parts of an object?
Removed
Which of the following terms is/are used to indicate specific measured distances from the datum and/or other points identified by the manufacturer, to points in or on the aircraft? Zone numbers reference numbers station numbers
Station Numbers
What happens to the current in a voltage step-up transformer with a ratio of 1 to 4?
The current is stepped down by a 1 to 4 ratio
When referring to an electrical circuit diagram, what point is considered to be at zero voltage?
The ground reference
Which statement regarding the hydrometer reading of a lead-acid battery electrolyte is true? The hydrometer reading does not require a temperature correction if the electrolyte temperature is 80 deg A specific gravity correction should be added to the hydrometer reading if the electrolyte temperature is below 59 deg The hydrometer will give a true indication of the capacity of the battery regardless of the electrolyte tmperature
The hydrometer reading does not require a temperature correction if the electrolyte temperature is 80 deg
Which statement is applicable when using a sketch for making a part? The sketch may be used only if supplemented with three-view orthographic projection drawings The sketch must show all information to manufacture the part The sketch need not show all necessary construction details
The sketch must show all information to manufacture the part
What determines the amount of current which will flow through a battery while it is being charged by a constant voltage source?
The state-of-charge of the battery
Which statement is correct when made in reference to a parallel circuit? The current is equal in all portions of the circuit The total current is equal to the sum of the currents through the individual branches of the circuit The current in amperes can be found by dividing the EMF in volts by the sum of the resistors in ohms
The total current is equal to the sum of the currents through the individual branches of the circuit
Which effect does not apply to the movement of electrons flowing in a conductor?
Thermal energy
Which of the following best describes the operating principle in a nickel-cadmium battery installed in an aircraft? At full charge, the electrolyte will be at its lowest level and should be filled To completely charge a nickel-cadmium battery, some gassing must take place; thus, some water will be used When positive plates slowly give up oxygen, which is regained by the negative plates, the battery is charging
To completely charge a nickel-cadmium battery, some gassing must take place; thus, some water will be used
When referring to an electrical circuit diagram, what is the purpose of the ground symbol used in electrical circuit diagrams?
To show that there is a return path for the current between the source of electrical energy and the load
Which is correct concerning a parallel circuit? Total resistance will be smaller than the smallest resistor Total resistance will decrease when one of the resistances is removed Total voltage drop is the same as the total resistance
Total resistance will be smaller than the smallest resistor
Which requires the most electrical power during operation? (NOTE 1 HP=746 watts) A 12 volt motor requiring 8 amperes 4 30 watt lamps in a 12 volt parallel circuit 2 lights requiring 3 amperes each in a 24 volt parallel system
Two lights requiring 3 amperes each in a 24 volt parallel system
What unit is used to express electrical power?
Watt
Which of the following logic gates will provide an active high out only when all inputs are different?
XOR
What will a voltmeter read if properly connected across a closed switch in a circuit with electrical power on?
Zero voltage
A 14 ohm resistor is to be installed in a series circuit carrying .05 ampere. How much power will the resistor be required to dissipate?
at least 35 milliwatts
The working voltage of a capacitor in an AC circuit should be
at least 50 percent greater than the highest applied voltage
In a PNP transistor application, the solid state device is turned on when the
base is negative with respect to the emitter
In a NPN transistor application, the solid state device is turned on when the
base is positive with respect to the emitter
What should be the first step of the procedure in sketching an aircraft wing skin repair?
block in the views
In nickel-cadmium batteries, a rise in cell temperature
causes a decrease in internal resistance
Forward biasing of a solid state device will cause the device to
conduct
The method used to rapidly charge a nickel-cadmium battery utilizes
constant voltage and varying current
The end-of-charge voltage of a 19 cell nickel-cadmium battery measured while still on charge,
depends upon its temperature and the method used for charging
Working drawings may be divided into three classes. They are:
detail drawings, assembly drawings, and installation drawings
The measurements showing the ideal or "perfect" sizes of parts on drawings are called
dimmensions
A simple way to find the center of the circle on a sketch or drawing, or a circular piece of material is to
draw two nonparallel chord lines across the circle and then a corresponding perpendicular bisector line across each chord line
Unless otherwise specified, any values given for current or voltage in an AC circuit are assumed to be
effective values
Nickel-cadmium batteries which are stored for a long period of time will show a low liquid level because
electrolyte becomes absorbed into the plates
Electrostatic fields are known as
electrostatic fields
When different rated capacitors are connected in parallel in a circuit, the total capacitance is (NOTE: Ct=C1+C2...)
equal to the sum of all the capacitances
When inductors are connected in series in a circuit, the total inductance is ( where the magnetic fields of each inductor do not affect the others) NOTE: Lt=L1+L2...
equal to the sum of the individual inductances
A cabin entry light of 10 watts and a dome light of 20 watts are connected in parallel to a 30 volt source. If the voltage across the 10 watt light is measure, it will be
equal to the voltage across the 20 watt light
Sketches are usually made easier by the use of
graph paper
The term that describes the combinded resistive forces in an AC circuit is
impedance
The electrolyte of a nickel-cadmium battery is the lowest when the battery is
in a discharged condition
The electrolyte of a nickel-cadmium battery is highest when the battery is
in a fully charged position
The correct way to connect a test voltmeter in a circuit is
in parallel with a unit
The basis for transformer operation is in the use of alternating current is mutual
inductance
The opposition offered by a coil to the flow of alternating current is called (disregard resistance)
inductive reactance
Transfer of electric energy from one circuit to another without aid of electrical connections
is called induction
When calculating power in a reactive or inductive AC circuit, the true power is
less than the apparent power
In an AC circuit, the effective voltage is
less than the maximum instantaneous voltage
Zone numbers on aircraft blueprints are used to
locate parts, sections, and views on large drawings
A fully charged lead-acid battery will not freeze until extremely low temperatures are reached because
most of the acid is in the solution
Convert farads to microfarads by
multiplying farads by 10 to the power of 6
The presence of any small amount of potassium carbonate deposits on the top of nickel-cadmium battery cells in service is an indication of normal operation excessive gassing plate sulfation
normal operation
A thermal switch, or thermal protector, as used in an electric motor, is designed to
open the circuit in order to allow cooling of the motor
The amount of electricity a capacitor can store is directly proportional to the
plate area and inversely proportional to the distance between the plates
The purpose of providing a space underneath the plates in a lead-acid battery's cell container is to
prevent sediment buildup from contacting the plates and causing a short circuit
Diodes are used in electrical power supply circuits primarily as
rectifiers
Capacitors are sometimes used in DC circuits to
smooth out slight pulsations in current/voltage
A specific measured distance from the datum or some other point identified by the manufacturer, to a point in or on the aircraft is called a zone number reference number station number
station number
The voltage drop in a circuit of known resistance is dependent on
the amperage of the circuit
When a charging current is applied to a nickel-cadmium battery the cells emit gas
towards the end of the charging cycle
For sketching purposes. almost all objects are composed of one or some combination of six basic shapes; these include the
triangle, plane, circle, line, square, and sphere
Typical application for zener diodes is as
voltage regulators
The potential difference between two conductors which are insulated from each other is measured in
volts
