General Exam AVMT
What is the total capacitance of a circuit containing three capacitors with a capacitance of .02 microfarad, .05 microfarad, and .10 microfarad, respectively?
.0125 uF
What is the total capacitance of a circuit containing three capacitors in parallel with capacitances of .02 microfarad, .05 microfarad, and .10 microfarad, respectively?
.170 uF
What is the total capacitance of a certain circuit containing three capacitors with capacitances of .25 microfarad, .03 microfarad, and .12 microfarad, respectively?
.4 uF
A lead-acid battery with 12 cells connected in series (no-load voltage = 2.1 V per cell) furnishes 10 amperes to a load of 2-ohms resistance. The internal resistance of the battery in this instance is
0.52 ohms
If three resistors of 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 amps
A 12-volt electric motor has 1,000 watts input and 1 horsepower output. Maintaining the same efficiency, how much input power will a 24 volt, 1 horsepower electric motor require?
1,000 watts
What is the impedance of an AC-Series circuit consisting of an inductor with a reactance of 10 ohms, a capacitor with a reactance of 4 ohms, and a resistor with a resistance of 8 ohms?
10 Ohms
A circuit has an applied voltage of 30 volts and a load 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
.002KV equals
2.0 Volts
A 24V source is required to furnish 48W to a parallel circuit consisting of two resistors of equal value. What is the value of each resistor?
24 Ohms
In a parallel circuit with four 6-ohm resistors across 24V battery, what is the total voltage across resistor-three in the circuit?
24 Volts
A 24V source is required to furnish 48W to a parallel circuit consisting of four resistors of equal value. What is the voltage drop across each resistor?
24V
How many amperes will a 28-volt generator be required to supply to a circuit containing five lamps in parallel, three of which have a resistance of 6 ohms each and two of which have a resistance of 5 ohms each?
25.23 amperes
What is the operating resistance of a 30W light bulb designed for a 28V system?
26Ohms
A 48V source is required to furnish 192W to a parallel circuit consisting of three 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? One motor 75% 1/5 HP Three position lights 20W each One heating element 5 amp One anticollision light 3 amp (Note: 1 horsepower = 746 W)
450 Watts
In a parallel circuit with three 6-ohm resistors across a 12V battery, what is the total current value in the circuit?
6 amps
A 1-horsepower, 24-volt DC electric motor that is 80% efficient requires 932.5 watts. How much power will a 1 hp, 12V DC electric motor that is 75% efficient require?
994.6 Watts
Which required more electrical power?
A 1/5 hp, 24V motor which is 75% efficient
If electrolyte from a lead-acid battery is spilled in the battery compartment, which procedure should be followed?
Apply sodium bicarbonate solution to the affected area followed by a water rinse
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
Which of the following statements is true regarding the charging of several aircraft batteries together?
Batteries of different voltages but similar capacities (can be connected in series) as well as same voltage and same ampere-hour capacity (must be connected in series) with each other across the charger and charged using the constant current method.
What should be the first step of the procedure in sketching an aircraft wing skin repair?
Block in the views
1. A detail drawing is a description of a single part 2. an assembly drawing is a description of an object made up of two or more parts
Both are true
How can the state-of-charge of a nickel-cadmium battery be determined?
By a measured discharge
What is the likely result of servicing and charging nickel-cadmium and lead acid batteries together in the same service area?
Contamination of both types of batteries
What is the basic unit of electrical quantity?
Coulomb
Which of these will cause the resistance of a conductor to decrease?
Decrease the length or increase the cross-sectional area
What is the class of working drawing that is the description/depiction of a single part?
Detail drawing
Working drawings may be divided into three classes. They are:
Detail drawings, assembly drawings, and installation drawings
Which of the following are commonly used as rectifiers in electrical circuits?
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
Which condition is an indication of improperly torqued cell link connections of a nickel-cadmium battery?
Heat or burn marks on the hardware
Which is correct in reference to the electrical resistance?
If one of three bulbs in a parallel lighting 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
What is the opposition to the flow of AC produced by a magnetic field with generated back voltage (EMF) called?
Inductive reactance
Through which material will magnetic lines of force pass the most readily?
Iron
Under which condition will a ground be provided for the warning horn through both gear switches when the throttles are closed?
Left gear up and right gear down
Which of the following best describes the contributing factors to thermal runaway in a nickel-cadmium battery installed in 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?
Miliampere
Which statement is true regarding an orthographic projection?
One view, two view, and three view drawings are the most common
1. Schematic diagrams indicate the location of individual components in the aircraft 2. Schematic diagrams indicate the location of components with respect to each other within the system
Only number 2 is true
1. According to 14 CFR part 91, repairs to an aircraft skin should have a detailed dimensional sketch included in the permanent records 2. On occasion, a mechanic may need to make a simple sketch of a proposed repair to an aircraft, a new design, or a modification. Regarding the above statements
Only number 2 is true.
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
Which effect does not apply to the movement of electrons flowing in a conductor?
Static energy
What happens to the current in a voltage step-up transformer with a ration 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 of a lead-acid storage battery electrolyte is true?
The hydrometer reading does not require a temperature correction of the electrolyte temperature is 80 degrees F
Which statement is applicable when using a sketch for making a part?
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 in a constant voltage source?
The state-of-charge of the battery
Which statement is correct when made in reference to a parallel circuit?
The total current is equal to the sum of the currents through the individual branches of the circuit
Which of the following best describes the operating principal in a nickel-cadmium battery installed in an aircraft?
To completely charge a nickel-cadmium battery, some gassing must take place; thus, some water will be used
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.
Which requires the most electrical power during operation?
Two lights requiring 3 amps each in a 24-volt parallel system
The potential difference between two conductors which are insulated form each other is measured in
Volts
What unit is used to express electrical power?
Watts
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
The working voltage of a capacitor in an AC circuit should be
at least 50 percent greater than the highest applied voltage
In a P-N-P transistor application, the solid state device is turned on when the
base is negative with respect to the emitter
In a N-P-N transistor application, the solid state device is turned on when the
base is positive with respect to the emitter
In nickel-cadmium batteries, a rise in cell temperature
causes a decrease in internal resistance
Forward biasing of a solid stat 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
Electrostatic fields are also known as
dielectric fields
A simple way to find the center of a circle on a sketch or drawing, or a circular piece of material is to
draw two non-parallel chord lines across the circle and then a corresponding perpendicular bisector lines 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
When different rated capacitors are connected in parallel in a circuit, the total capacitance is
equal to the sum of all the capacitances
When indicutors are connected in series in a circuit, the total inductance is
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 measured, it will be
equal to the voltage across the 20-watt light
A line used to show an edge which is not visible is a
hidden line
The term that describes the combined 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 condition
The correct way to connect a test voltmeter in a circuit is
in parallel with a unit
The basis for transformer operation 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 the 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
When different rated capacitors are connected in series in a circuit, the total impedance is
less than the capacitance of the lowest rated capacitor
When more than two inductors of different inductances are connected in parallel in a circuit, the total inductance is
less than the inductance of the lowest rated inductor
In an AC circuit, the effective voltage is
less than the maximum instantaneous voltage
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 picofarads by
multiplying farads by 10 to the power of 12
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
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 control valve switch must be placed in the neutral position when the landing gears are down to
prevent the warning horn from sounding when the throttles are closed
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
station number
The total 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
toward 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, circle, cube, cylinder, cone, and sphere
Typical application for zener diodes is as
voltage regulators