Tüm alıştırma soruları

Soru 1061Soru →

When preparing an electrical wire with a standard multi-gauge wire stripper, what is the primary purpose of selecting the notch that matches the wire's American Wire Gauge (AWG) size?

To trim both the metal conductor and the insulation flush in a single cut

To slice through the insulation cleanly without nicking or cutting the metal conductor

To compress the insulation tightly against the conductor to prevent electrical shorts

To heat and soften the outer insulation before sliding it off the conductor

Cevabı ve açıklamayı göster

Cevap: To slice through the insulation cleanly without nicking or cutting the metal conductor

Cevap

To slice through the insulation cleanly without nicking or cutting the metal conductor

Selecting the matching gauge notch ensures the cutting edges penetrate only the depth of the plastic or rubber insulation jacket. This allows the insulation to be pulled free cleanly while leaving the inner conductor structurally intact without nicks or broken strands.

Adım Adım Çözüm

1

Identify the primary function of a wire stripper.

Wire strippers remove the non-conductive insulation jacket to expose the bare metallic wire for electrical termination.

Electrical connections require direct metallic contact with the bare conductor.

2

Analyze how wire stripper notches operate based on AWG sizing.

Each notch is precision-machined to match the exact diameter of the metallic core for a specific gauge size.

When closed, the blades cut entirely through the insulation while leaving sufficient clearance so the core wire is not scored, weakened, or severed.

Anahtar Kavram

Operating principle and gauge selection of wire stripping tools

Tahmini Süre:45s

Soru 1062Soru →

Match each internal engine component to its primary mechanical role in an internal combustion engine.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

Crankshaft matches conversion of reciprocating motion to rotational torque; Camshaft matches valve actuation and timing; Connecting rod matches force transmission from piston to crank journal; Flywheel matches inertial smoothing of power pulses.

Each internal component fulfills a dedicated mechanical purpose in four-stroke engine operation: the crankshaft handles motion conversion from reciprocating to rotary; the camshaft governs valvetrain operation; the connecting rod acts as the dynamic mechanical linkage between piston and crank; and the flywheel stabilizes rotational speed via kinetic inertia.

Adım Adım Çözüm

1

Identify the primary shaft responsible for converting linear reciprocating motion to rotation.

The crankshaft receives vertical downward force and translates it into rotating engine output.

Vehicular drivetrains require rotational power generated from the linear stroke of the pistons.

2

Identify the component that regulates intake and exhaust flow in synchrony with engine rotation.

The camshaft utilizes mechanical lobes to open and close the valves at specified intervals.

Valves must operate in precise coordination with the four-stroke combustion cycle.

3

Determine the structural member connecting the piston assembly to the rotating assembly.

The connecting rod pivots on the wrist pin and clamps around the crank throw.

It must pivot dynamically while enduring high mechanical compressive and tensile loads.

4

Identify the inertial damper and energy storage mass on the engine crankshaft.

The flywheel maintains angular momentum across intermittent power strokes.

Combustion occurs periodically, requiring inertial storage to ensure smooth continuous crank rotation.

Anahtar Kavram

Internal Combustion Core Component Mechanics and Motion Conversion

Tahmini Süre:1m 0s

Soru 1063Soru →

Four-band resistors use standardized color bands to indicate numerical resistance values. Match each resistor color band with its correct numerical digit value.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

Brown matches with digit value of

1

, Orange matches with digit value of

3

, Blue matches with digit value of

6

, and Gray matches with digit value of

8

.

According to the standard EIA resistor color code: Brown represents 1, Orange represents 3, Blue represents 6, and Gray represents 8.

Adım Adım Çözüm

1

Recall the standard electronic color code sequence from 0 through 9.

The standardized sequence is Black (0), Brown (1), Red (2), Orange (3), Yellow (4), Green (5), Blue (6), Violet (7), Gray (8), and White (9).

Each color band on a fixed resistor corresponds to an exact base-10 numerical value.

2

Pair each given color band to its corresponding numerical digit.

Brown = 1, Orange = 3, Blue = 6, and Gray = 8.

Direct mapping using the standard EIA color code chart.

Anahtar Kavram

Standard Resistor Color Code Digit Values

Tahmini Süre:35s

Soru 1064Soru →

During internal combustion engine operation, various internal components perform distinct mechanical functions to sustain the four-stroke operating cycle. Match each engine component on the left with its primary operational role on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

Crankshaft pairs with transforming reciprocating linear motion into rotary output torque; Camshaft pairs with regulating valve timing; Connecting Rod pairs with transferring combustion thrust from the wrist pin to the rod journal; Piston Rings pair with maintaining combustion chamber seal and metering cylinder wall oil film.

Each internal component occupies a specialized mechanical station: the crankshaft converts reciprocating piston stroke into rotational engine torque; the camshaft precisely governs valve lift and duration synchronized to engine rotation; the connecting rod forms the intermediate structural bridge between the piston pin and crank journal; and the piston rings provide combustion chamber sealing, heat dissipation to the cylinder wall, and oil control.

Adım Adım Çözüm

1

Analyze the motion conversion mechanism in the crankcase.

Identified the crankshaft as the primary rotating shaft converting vertical linear movement of the pistons into rotational torque.

Internal combustion engines rely on the crankshaft's offset crankpins to convert reciprocating kinetic energy into rotating mechanical output.

2

Examine the valvetrain synchronization component.

Identified the camshaft as the component whose lobes mechanically actuate the intake and exhaust valves according to the 4-stroke cycle.

The camshaft turns at half the speed of the crankshaft to open each valve once every 720 degrees of crank rotation.

3

Determine the link between the piston and the rotating crankshaft.

Identified the connecting rod as the structural link with a small end attached to the piston wrist pin and a big end attached to the crank journal.

The connecting rod must pivot dynamically while transferring extreme downward pressure created during the power stroke.

4

Identify the dynamic sealing and oil scraping element.

Identified the piston rings as the spring-loaded metallic rings mounted on the piston circumference.

Piston rings maintain high cylinder compression by preventing gas leakage into the oil pan while managing oil film thickness along the cylinder bore.

Anahtar Kavram

Internal combustion engine mechanical architecture and dynamic component functions

Tahmini Süre:1m 30s

Soru 1065Soru →

Match each electrical load scenario on the left with its corresponding steady-state power dissipation on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

The fan motor (

12\text{ V}, 2.5\text{ A}

) matches

30\text{ W}

; the shunt resistor (

0.5\text{ }\Omega, 8\text{ A}

) matches

32\text{ W}

; the heating element (

24\text{ V}, 16\text{ }\Omega

) matches

36\text{ W}

; and the parallel resistors (

50\text{ V}, 2 \times 50\text{ }\Omega

) match

100\text{ W}

.

Each load condition requires selecting the appropriate formula derived from Watt's Law and Ohm's Law:

P = VI

yields

30\text{ W}

for the motor;

P = I^2R

yields

32\text{ W}

for the current shunt;

P = \frac{V^2}{R}

yields

36\text{ W}

for the heating resistor; and parallel reduction with

P = \frac{V^2}{R_{eq}}

yields

100\text{ W}

for the dual load.

Adım Adım Çözüm

1

Calculate the power consumed by the cooling fan motor using

P = V \times I

.

P = 12\text{ V} \times 2.5\text{ A} = 30\text{ W}

When voltage and current are explicitly provided, the direct product gives the electrical power.

2

Calculate the power dissipated in the shunt resistor using

P = I^2 \times R

.

P = (8\text{ A})^2 \times 0.5\text{ }\Omega = 64 \times 0.5 = 32\text{ W}

When current and resistance are known, squaring the current and multiplying by resistance gives power dissipation.

3

Calculate the power dissipated in the heating element using

P = \frac{V^2}{R}

.

P = \frac{(24\text{ V})^2}{16\text{ }\Omega} = \frac{576}{16} = 36\text{ W}

When voltage across a component and its resistance are known, dividing the squared voltage by the resistance gives the dissipated power.

4

Determine the equivalent parallel resistance of the two

50\text{ }\Omega

resistors and calculate total circuit power.

R_{eq} = \frac{50\text{ }\Omega \times 50\text{ }\Omega}{50\text{ }\Omega + 50\text{ }\Omega} = 25\text{ }\Omega

;

P = \frac{(50\text{ V})^2}{25\text{ }\Omega} = \frac{2500}{25} = 100\text{ W}

Combining parallel branches determines the total circuit load before applying the power equation.

Anahtar Kavram

Calculation of electrical power dissipation across varied circuit configurations using Watt's Law formulas (

P = VI

,

P = I^2R

, and

P = \frac{V^2}{R}

).

Tahmini Süre:2m 0s

Soru 1066Soru →

A flight engineer is monitoring the fuel consumption, in gallons per hour (GPH), of a cargo aircraft during $4$ different flight legs. The consumption for the first $3$ legs was $520$ , $480$ , and $550$ GPH.

If the target mean fuel consumption for all $4$ legs is $510$ GPH, what must the fuel consumption be for the $4$ th leg?

490

500

515

530

Cevabı ve açıklamayı göster

Cevap: 490

Cevap

490

To find the missing value when given the mean, first determine the total sum required for all data points. Since the mean for

4

legs is

510

GPH, the total fuel consumption must be

4 \times 510 = 2040

GPH. The sum of the first three legs is

520 + 480 + 550 = 1550

GPH. Subtracting this sum from the required total gives the fuel consumption required for the fourth leg:

2040 - 1550 = 490

GPH.

Adım Adım Çözüm

1

Set up the formula for the mean of

4

flight legs.

\frac{520 + 480 + 550 + x}{4} = 510

The mean is calculated by dividing the sum of all values by the total number of values.

2

Calculate the total target fuel consumption required for all

4

legs.

510 \times 4 = 2040

Multiplying the target mean by the total number of legs gives the required overall sum.

3

Calculate the sum of the fuel consumption for the first

3

legs.

520 + 480 + 550 = 1550

This represents the total fuel consumed so far.

4

Subtract the sum of the first

3

legs from the total target consumption to find the missing value.

2040 - 1550 = 490

The difference between the required total and the current total must be the consumption of the

4

th leg.

Anahtar Kavram

Calculating a missing value when given the mean

Soru 1067Soru →

An audio technician connects an oscilloscope to analyze a recurring tone from a signal generator. The horizontal Time/Div control is set to $250\text{ }\mu\text{s/div}$ . On the graticule display, exactly two complete cycles of the sine wave span $8\text{ horizontal divisions}$ . What is the frequency of the audio signal?

500\text{ Hz}

1\text{ kHz}

4\text{ kHz}

100\text{ Hz}

Cevabı ve açıklamayı göster

Cevap: $1\text{ kHz}$

Cevap

The frequency of the audio signal is

1\text{ kHz}

(

1{}000\text{ Hz}

).

One complete sine wave cycle occupies

\frac{8\text{ divisions}}{2} = 4\text{ divisions}

. Multiplying by the horizontal timebase of

250\text{ }\mu\text{s/div}

gives a period of

T = 1{}000\text{ }\mu\text{s} = 1\text{ ms} = 0.001\text{ s}

. The frequency is

f = \frac{1}{T} = \frac{1}{0.001\text{ s}} = 1{}000\text{ Hz} = 1\text{ kHz}

.

Adım Adım Çözüm

1

Determine the number of horizontal divisions occupied by one complete cycle.

\text{Divisions per cycle} = \frac{8\text{ divisions}}{2\text{ cycles}} = 4\text{ div/cycle}

The period of a periodic wave is defined by the horizontal duration of one full cycle.

2

Calculate the period (

T

) of the waveform by multiplying divisions per cycle by the horizontal timebase scale.

T = 4\text{ div} \times 250\text{ }\mu\text{s/div} = 1000\text{ }\mu\text{s} = 1 \times 10^{-3}\text{ s}

The Time/Div control establishes the time value represented by each graticule division.

3

Calculate the frequency (

f

) using the reciprocal formula

f = \frac{1}{T}

.

f = \frac{1}{1 \times 10^{-3}\text{ s}} = 1000\text{ Hz} = 1\text{ kHz}

Frequency is the inverse of the period in seconds.

Anahtar Kavram

Calculating waveform period and frequency from oscilloscope horizontal timebase settings and graticule divisions.

Tahmini Süre:1m 0s

Soru 1068Soru →

Thermal-magnetic circuit breakers utilize two distinct internal mechanisms to provide comprehensive circuit protection. Which internal component provides an instantaneous trip to protect against severe short-circuit conditions?

A bimetallic strip that flexes as it gradually heats up

An electromagnet that immediately pulls an armature to release the trip latch

A metal oxide varistor that clamps high voltage surges

A parallel shunt resistor that diverts short-circuit current to ground

Cevabı ve açıklamayı göster

Cevap: An electromagnet that immediately pulls an armature to release the trip latch

Cevap

An electromagnet that immediately pulls an armature to release the trip latch

Thermal-magnetic circuit breakers combine two tripping methods: thermal and magnetic. The magnetic component consists of an electromagnetic coil placed in series with the line. Under a severe fault such as a direct short circuit, the sudden surge in current generates an intense magnetic field that instantly draws an armature toward the coil, unlatching the switch mechanism within milliseconds to disconnect power safely.

Adım Adım Çözüm

1

Identify the dual-protection mechanisms used inside thermal-magnetic circuit breakers.

The breaker includes a thermal element (bimetallic strip) for prolonged, moderate overloads and a magnetic element (electromagnetic coil) for large, instantaneous fault currents.

Different types of overcurrent faults require different response times to protect wiring without causing nuisance tripping during normal startup surges.

2

Determine which mechanism is designed to trigger instantly during a dead short circuit.

A short circuit causes a massive and immediate spike in current, which energizes the electromagnetic coil strongly enough to instantly attract a movable armature and mechanically trip the contact mechanism.

Electromagnetic response does not depend on slow thermal accumulation, allowing contact separation within milliseconds.

Anahtar Kavram

Dual-trip operational principles of thermal-magnetic circuit breakers

Tahmini Süre:1m 0s

Soru 1069Soru →

A technician needs to measure the direct current flowing through a $12\text{ V}$ automotive cooling fan circuit that is expected to draw approximately $3.2\text{ A}$ . Which multimeter configuration and connection method must be used to obtain an accurate reading without damaging the meter or blowing its internal fuse?

Insert the red probe into the

\text{V}/\Omega/\text{mA}

jack, black probe into

\text{COM}

, select the

\text{DC mA}

dial setting, and connect the meter in series with the motor.

Insert the red probe into the

10\text{ A}

jack, black probe into

\text{COM}

, select the

\text{DC A}

dial setting, and connect the meter in series with the motor.

Insert the red probe into the

10\text{ A}

jack, black probe into

\text{COM}

, select the

\text{DC A}

dial setting, and connect the test probes in parallel across the motor terminals.

Insert the red probe into the

10\text{ A}

jack, black probe into

\text{COM}

, select the

\text{AC A}

dial setting, and connect the meter in series with the motor.

Cevabı ve açıklamayı göster

Cevap: Insert the red probe into the $10\text{ A}$ jack, black probe into $\text{COM}$ , select the $\text{DC A}$ dial setting, and connect the meter in series with the motor.

Cevap

Insert the red probe into the

10\text{ A}

jack, black probe into

\text{COM}

, select the

\text{DC A}

dial setting, and connect the meter in series with the motor.

Measuring current requires placing the multimeter in series with the load so all electron flow passes through the instrument. Because the expected current is

3.2\text{ A}

, the positive lead must be plugged into the high-current

10\text{ A}

input jack to prevent blowing the lower-rated milliamp fuse. Furthermore, because the source is automotive

12\text{ V DC}

, the function dial must be configured to direct current (

\text{DC A}

).

Adım Adım Çözüm

1

Select the appropriate current range and input jack based on anticipated current magnitude.

The red lead must be placed in the dedicated

10\text{ A}

high-current jack rather than the

\text{V}/\Omega/\text{mA}

jack.

The circuit draws approximately

3.2\text{ A}

(

3200\text{ mA}

), which far exceeds the standard

200\text{ mA}

or

500\text{ mA}

limit of the fused low-current jack.

2

Set the multimeter function selector switch to the correct electrical mode.

The selector switch must be rotated to the direct current amperes (

\text{DC A}

or

A\overline{--}

) position.

An automotive fan operates on a direct current (

12\text{ V DC}

) source, requiring the meter to measure unidirectional current flow rather than alternating current.

3

Connect the multimeter probes properly into the physical circuit.

Break the circuit path and place the meter leads in series with the load.

Current represents the rate of charge flow through a conductor; therefore, all current must flow through the meter's low internal shunt resistor in series to be measured.

Anahtar Kavram

Multimeter Current Measurement and Input Jack Protection

Tahmini Süre:1m 15s

Soru 1070Soru →

A direct-current (DC) relay coil has an internal resistance of $80\ \Omega$ and draws a steady current of $250\text{ mA}$ . How much electrical power is dissipated by the coil?

20\text{ W}

5{}000\text{ W}

5\text{ W}

320\text{ W}

Cevabı ve açıklamayı göster

Cevap: $5\text{ W}$

Cevap

The electrical power dissipated by the coil is

5\text{ W}

.

To find the power dissipated when current and resistance are known, apply Watt's Law in the form

P = I^2 R

. First, convert

250\text{ mA}

to

0.25\text{ A}

. Squaring the current gives

(0.25\text{ A})^2 = 0.0625\text{ A}^2

. Multiplying by the resistance yields

0.0625\text{ A}^2 \times 80\ \Omega = 5\text{ W}

.

Adım Adım Çözüm

1

Convert the current from milliamperes (mA) to amperes (A).

I = 250\text{ mA} = 0.25\text{ A}

Standard electrical formulas require current in base units of amperes.

2

Calculate the power dissipation using Watt's Law (

P = I^2 R

).

P = (0.25\text{ A})^2 \times 80\ \Omega = 0.0625\text{ A}^2 \times 80\ \Omega = 5\text{ W}

When current and resistance are known, power equals the square of current multiplied by resistance.

Anahtar Kavram

Calculating electrical power using current and resistance (

P = I^2 R

) with metric prefix conversion.

Tahmini Süre:1m 0s

Soru 1071Soru →

An electronics technician evaluates how different physical modifications alter the electrical resistance of solid wire conductors based on the fundamental relationship $R = \rho \frac{L}{A}$ . Match each conductor modification on the left with its exact resulting effect on electrical resistance on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

Doubling conductor length doubles resistance; doubling diameter reduces resistance to one-fourth; replacing copper with nichrome increases resistance due to higher resistivity; increasing metal temperature increases resistance due to thermal lattice vibrations.

Each physical conductor property maps directly to the governing formula

R = \rho \frac{L}{A}

and temperature coefficient behavior. Length is directly proportional (

2L \rightarrow 2R

), diameter has an inverse-square relationship (

2d \rightarrow 4A \rightarrow \frac{1}{4}R

), material change alters

\rho

, and thermal excitation increases atomic collisions in metals.

Adım Adım Çözüm

1

Analyze the effect of length change using

R = \rho \frac{L}{A}

Since

R \propto L

, multiplying length by

2

multiplies resistance by

2

.

Electrons must traverse twice as much resistive medium, doubling opposition to flow.

2

Analyze the effect of diameter change using cross-sectional area

A = \frac{\pi d^2}{4}

Doubling

d

yields

(2d)^2 = 4A

. Since

R \propto \frac{1}{A}

, resistance becomes

\frac{R}{4}

.

Resistance varies inversely with the square of the conductor diameter.

3

Analyze material substitution from copper to nichrome

Nichrome has a higher resistivity (

\rho

) than copper.

Resistivity is an intrinsic material property that directly scales total resistance.

4

Analyze thermal effects on metallic conductors

Resistance increases with temperature in standard metals.

Thermal energy increases lattice atom vibrations, creating more frequent collisions with moving valence electrons.

Anahtar Kavram

Physical factors determining conductor resistance: length, cross-sectional area, resistivity, and temperature

Tahmini Süre:1m 15s

Soru 1072Soru →

Which internal engine component connects the piston to the crankshaft to convert the piston's linear up-and-down motion into rotary motion?

Camshaft

Connecting rod

Rocker arm

Intake manifold

Cevabı ve açıklamayı göster

Cevap: Connecting rod

Cevap

Connecting rod

The connecting rod provides the physical mechanical link between the piston and the crankshaft. As combustion forces the piston downward in a linear path inside the cylinder cylinder bore, the connecting rod pivots on the wrist pin and pushes the offset crank journal, converting reciprocating motion into the rotary motion needed to drive the vehicle.

Adım Adım Çözüm

1

Identify the motion types of the piston and the crankshaft.

The piston travels in a straight line up and down inside the cylinder (reciprocating motion), while the crankshaft spins on its main bearings (rotary motion).

Internal combustion engines rely on mechanical linkages to bridge the linear expansion of burning gases into usable rotational work.

2

Determine which component links these two parts together.

The connecting rod connects to the piston via the wrist pin at its small end and to the crankshaft journal at its large end.

This structural connection allows the rod to pivot as the piston pushes downward, forcing the offset crankshaft journal to rotate.

Anahtar Kavram

Reciprocating to rotary motion conversion via the connecting rod

Tahmini Süre:30s

Soru 1073Soru →

A technician is troubleshooting a circuit where two identical heating elements, $R_1$ and $R_2$ , are connected in series across a $120\text{ V}$ AC supply. When the circuit is energized, neither element produces heat. Using a digital multimeter set to AC voltage, the technician measures $0\text{ V}$ across $R_1$ and $120\text{ V}$ across $R_2$ . Based on these measurements, which of the following is the most likely fault in the circuit?

R_1

has developed a short circuit.

R_2

has developed an open circuit.

R_2

has developed a short circuit.

R_1

has developed excessive contact resistance.

Cevabı ve açıklamayı göster

Cevap: $R_2$ has developed an open circuit.

Cevap

The heating element

R_2

has an open circuit.

In a series circuit containing an open fault, the current drops to zero throughout the loop. According to Ohm's Law (

V = I \times R

), any intact component drops

0\text{ V}

because no current flows through it. Consequently, the entire source potential of

120\text{ V}

appears directly across the terminals of the open element (

R_2

).

Adım Adım Çözüm

1

Analyze current flow in the series circuit based on operating symptoms.

Because neither series element produces heat, the total circuit current is zero (

I = 0\text{ A}

).

In a series circuit, any break in continuity stops current through all components.

2

Apply Ohm's Law to the intact component

R_1

.

V_{R1} = I \times R_1 = 0\text{ A} \times R_1 = 0\text{ V}

.

Without current flow, no potential difference develops across an intact resistor.

3

Evaluate the voltage drop across the faulted component

R_2

.

V_{R2} = 120\text{ V}

(entire supply voltage).

An open component represents infinite resistance, placing the multimeter in series with the line voltage across the open gap, thereby reading full source voltage.

Anahtar Kavram

In a series circuit, an open component prevents current flow through all other components and drops the entire applied source voltage across the open point.

Soru 1074Soru →

During a diagnostic inspection of a four-stroke internal combustion engine, a technician notes that the crankshaft has completed exactly $180^\circ$ of rotation since the start of the intake stroke. As the piston now begins moving upward toward Top Dead Center (TDC), which operational state and cylinder event are occurring?

The exhaust valve is open while upward piston travel expels spent combustion gases into the exhaust manifold.

Both the intake and exhaust valves are closed while upward piston travel compresses the trapped air-fuel mixture.

The intake valve remains open while upward piston travel creates high vacuum to draw in additional fuel mixture.

Both valves are closed while high-pressure burning gases force the piston downward to generate crankshaft torque.

Cevabı ve açıklamayı göster

Cevap: Both the intake and exhaust valves are closed while upward piston travel compresses the trapped air-fuel mixture.

Cevap

Both the intake and exhaust valves are closed while upward piston travel compresses the trapped air-fuel mixture.

In a four-stroke internal combustion engine, each complete stroke corresponds to

180^\circ

of crankshaft rotation. The intake stroke occurs from

0^\circ

to

180^\circ

(TDC to BDC). From

180^\circ

to

360^\circ

, the engine executes the compression stroke, during which the piston travels upward from BDC to TDC with both the intake and exhaust valves completely sealed to compress the air-fuel mixture.

Adım Adım Çözüm

1

Determine the cycle phase corresponding to the crankshaft degree position.

The intake stroke spans

0^\circ

to

180^\circ

(piston moving downward from TDC to BDC). The next

180^\circ

(

180^\circ

to

360^\circ

) represents the compression stroke, where the piston travels upward from BDC to TDC.

Each stroke in a four-stroke internal combustion engine corresponds to

180^\circ

of crankshaft rotation (

720^\circ

total for all four strokes).

2

Identify the required valve positions and internal cylinder state during the compression stroke.

Both the intake valve and exhaust valve must be closed and fully seated against their valve seats.

Sealing the cylinder ensures the upward movement of the piston compresses the trapped air-fuel charge into the combustion chamber without leakage.

Anahtar Kavram

Four-stroke cycle timing and internal valve/piston kinematics

Tahmini Süre:1m 15s

Soru 1075Soru →

A single-cylinder engine produces driving force only during the combustion event, yet it continues to rotate smoothly across all other cycle phases. Which component attached to the crankshaft stores rotational energy to maintain continuous momentum during the non-power phases?

Connecting rod

Flywheel

Camshaft

Piston wrist pin

Cevabı ve açıklamayı göster

Cevap: Flywheel

Cevap

Flywheel

The flywheel is a heavy disc attached to the crankshaft that provides rotational inertia. Because internal combustion engines only deliver positive torque during the power stroke, the flywheel stores kinetic energy during combustion and uses its momentum to keep the crankshaft rotating through the intake, compression, and exhaust strokes.

Adım Adım Çözüm

1

Analyze energy generation across the four-stroke cycle

In a four-stroke engine, mechanical power is delivered exclusively during the power stroke when expanding combustion gases push the piston downward.

Understanding where engine torque originates highlights the need for a mechanism to sustain crankshaft movement through the intake, compression, and exhaust strokes.

2

Identify the internal component engineered to store rotational kinetic energy

The flywheel is a heavy disc bolted to the end of the crankshaft that possesses significant rotational inertia.

Its mass smooths out torque pulses by capturing kinetic energy during combustion and releasing it to turn the crankshaft during the remaining non-power strokes.

Anahtar Kavram

Flywheel function and momentum continuity in the four-stroke cycle

Tahmini Süre:45s

Soru 1076Soru →

A technician needs to protect a sensitive electronic component from stray external DC magnetic fields by placing it inside a soft iron enclosure. How does this magnetic shield prevent external magnetic flux from reaching the component?

The enclosure acts as a magnetic insulator, stopping and absorbing magnetic flux before it penetrates the surface.

The enclosure provides a low-reluctance path with high permeability, channeling the flux lines through its walls and around the interior.

The enclosure develops opposing magnetic poles that repel external magnetic field lines away from both sides of the casing.

The enclosure converts incoming magnetic lines of force into an electrostatic charge that is dissipated as heat.

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Cevap: The enclosure provides a low-reluctance path with high permeability, channeling the flux lines through its walls and around the interior.

Cevap

The enclosure provides a low-reluctance path with high permeability, channeling the flux lines through its walls and around the interior.

Magnetic shielding relies on high permeability and low reluctance. Because there is no known insulator that blocks magnetic flux lines, the soft iron shield provides an easy path of low reluctance that channels the magnetic field lines through its walls, directing them safely around the internal cavity where the sensitive component is placed.

Adım Adım Çözüm

1

Identify the magnetic characteristics of the shielding material.

Soft iron is a ferromagnetic substance characterized by high magnetic permeability and low magnetic reluctance.

Permeability describes how readily a material conducts magnetic flux compared to surrounding air, while reluctance represents opposition to flux lines.

2

Determine the path magnetic flux lines follow when encountering the enclosure.

Magnetic flux lines naturally follow the path of least resistance (lowest reluctance), concentrating within the thick iron walls.

Flux lines take the easiest path available rather than crossing the higher-reluctance air gap in the center.

3

Conclude how the interior component is protected.

Because flux lines are guided through the perimeter walls and exit on the opposite side, the internal cavity remains essentially free of magnetic field lines.

Since true magnetic insulators do not exist, diversion through high-permeability conduits is the fundamental method of magnetic shielding.

Anahtar Kavram

Magnetic Shielding, Permeability, and Reluctance

Tahmini Süre:1m 0s

Soru 1077Soru →

A radio technician is testing the output of an RF signal generator using an oscilloscope. The horizontal timebase control is set to $250\text{ }\mu\text{s/div}$ . On the screen graticule, a continuous sinusoidal waveform is observed where exactly $2.5\text{ complete cycles}$ span across $8\text{ horizontal divisions}$ . What is the frequency of this signal, in hertz ( $\text{Hz}$ )?

Cevabı ve açıklamayı göster

Cevap: 1250

Cevap

1250 Hz

The total duration of the

8\text{ horizontal divisions}

at

250\text{ }\mu\text{s/div}

is

2000\text{ }\mu\text{s}

(

2\text{ ms}

). Dividing by the

2.5\text{ complete cycles}

gives a period of

T = 800\text{ }\mu\text{s} = 0.0008\text{ s}

per cycle. Taking the reciprocal gives the frequency:

f = 1 / 0.0008\text{ s} = 1250\text{ Hz}

.

Adım Adım Çözüm

1

Calculate the total elapsed time across the observed graticule divisions.

Total time

= 8\text{ div} \times 250\text{ }\mu\text{s/div} = 2000\text{ }\mu\text{s}

The horizontal axis represents time, and the timebase setting indicates the duration per division.

2

Calculate the period (

T

) of a single cycle.

T = \frac{2000\text{ }\mu\text{s}}{2.5\text{ cycles}} = 800\text{ }\mu\text{s} = 800 \times 10^{-6}\text{ s} = 0.0008\text{ s}

The period is the time required to complete one single cycle.

3

Calculate the frequency (

f

) from the period.

f = \frac{1}{T} = \frac{1}{0.0008\text{ s}} = 1250\text{ Hz}

Frequency in hertz is the reciprocal of the period in seconds (

f = 1/T

).

Anahtar Kavram

Calculating waveform period and frequency from oscilloscope horizontal timebase settings and graticule divisions.

Tahmini Süre:1m 30s

Soru 1078Soru →

An electronics technician needs to attach a solderless ring terminal to the end of a stranded copper conductor. Which specialized wire preparation tool is designed to compress and permanently deform the terminal barrel onto the wire?

Diagonal cutters

Wire crimper

Wire stripper

Cable ripper

Cevabı ve açıklamayı göster

Cevap: Wire crimper

Cevap

Wire crimper

A wire crimper features contoured jaw nests specifically designed to exert uniform compressive force on a solderless connector barrel, creating a reliable mechanical and electrical joint without severing the conductor strands.

Adım Adım Çözüm

1

Identify the primary mechanical operation required by the task.

The task requires compressing and deforming a solderless terminal barrel around exposed conductor strands.

Solderless terminals require controlled mechanical deformation to form a gas-tight, low-resistance electrical and mechanical bond.

2

Select the appropriate electrical hand tool designed for this specific mechanical function.

The wire crimper (crimping tool) is the dedicated hand tool engineered with matching jaw cavities for terminal installation.

Other tools like strippers, cutters, and rippers perform material removal or severing rather than controlled compression.

Anahtar Kavram

Identification and proper application of wire crimping tools in electrical fabrication

Tahmini Süre:45s

Soru 1079Soru →

An oscilloscope is used to measure an alternating signal. The horizontal sweep rate (Time/Div) is set to $8\text{ }\mu\text{s/div}$ , and one complete cycle of the waveform spans exactly $5\text{ horizontal divisions}$ across the graticule. What is the frequency of this signal in kilohertz ( $\text{kHz}$ )?

Cevabı ve açıklamayı göster

Cevap: 25

Cevap

The frequency of the signal is

25\text{ kHz}

.

One full waveform cycle occupies

5

horizontal divisions at

8\text{ }\mu\text{s/division}

, giving a period of

T = 40\text{ }\mu\text{s}

(

40 \times 10^{-6}\text{ s}

). The frequency is the reciprocal of the period (

f = \frac{1}{T} = \frac{1}{40 \times 10^{-6}\text{ s}} = 25{}000\text{ Hz}

), which equals

25\text{ kHz}

.

Adım Adım Çözüm

1

Multiply the number of horizontal graticule divisions per cycle by the time base setting to find the period (

T

).

T = 5\text{ divisions} \times 8\text{ }\mu\text{s/div} = 40\text{ }\mu\text{s} = 40 \times 10^{-6}\text{ s}

Horizontal divisions represent the time dimension on an oscilloscope display.

2

Calculate the frequency (

f

) in hertz using the reciprocal relationship

f = \frac{1}{T}

.

f = \frac{1}{40 \times 10^{-6}\text{ s}} = 25{}000\text{ Hz}

Frequency is defined as the number of cycles per second.

3

Convert the resulting frequency from hertz (

\text{Hz}

) to kilohertz (

\text{kHz}

).

\frac{25{}000\text{ Hz}}{1{}000} = 25\text{ kHz}

The question specifies the final answer unit as kilohertz.

Anahtar Kavram

Calculating waveform period and frequency from oscilloscope horizontal Time/Div settings and graticule division counts

Tahmini Süre:1m 0s

Soru 1080Soru →

A security alarm control panel operates on a $12\text{ V}$ direct-current power supply connected across two parallel load branches. The first branch has a resistance of $20\ \Omega$ , and the second branch has a resistance of $30\ \Omega$ . What is the total current drawn by the alarm panel from the power supply?

0.24\text{ A}

0.60\text{ A}

1.0\text{ A}

144\text{ A}

Cevabı ve açıklamayı göster

Cevap: $1.0\text{ A}$

Cevap

The total current drawn by the alarm panel is

1.0\text{ A}

.

The total current of

1.0\text{ A}

is correct because each parallel branch experiences the full source voltage of

12\text{ V}

. Dividing the voltage by each branch resistance yields branch currents of

0.60\text{ A}

and

0.40\text{ A}

. Adding these together gives the total circuit current of

1.0\text{ A}

.

Adım Adım Çözüm

1

Calculate the current flowing through the first parallel branch (

I_1

)

I_1 = \frac{V}{R_1} = \frac{12\text{ V}}{20\ \Omega} = 0.60\text{ A}

In a parallel circuit, the full supply voltage of

12\text{ V}

appears across each individual branch.

2

Calculate the current flowing through the second parallel branch (

I_2

)

I_2 = \frac{V}{R_2} = \frac{12\text{ V}}{30\ \Omega} = 0.40\text{ A}

Apply Ohm's Law to the second branch using the constant supply voltage.

3

Sum the branch currents to determine total circuit current (

I_{\text{total}}

)

I_{\text{total}} = I_1 + I_2 = 0.60\text{ A} + 0.40\text{ A} = 1.0\text{ A}

According to Kirchhoff's Current Law, total current entering a parallel network equals the sum of all individual branch currents.

Anahtar Kavram

In a parallel DC circuit, voltage remains equal across all branches, and total source current equals the sum of the individual branch currents (

I_{\text{total}} = I_1 + I_2 + \dots + I_n

).

Alternatif Yöntem

Find total equivalent resistance using the product-over-sum formula:

R_{\text{total}} = \frac{R_1 \times R_2}{R_1 + R_2} = \frac{20 \times 30}{20 + 30} = \frac{600}{50} = 12\ \Omega

. Then calculate total current directly:

I_{\text{total}} = \frac{V}{R_{\text{total}}} = \frac{12\text{ V}}{12\ \Omega} = 1.0\text{ A}

.

Tahmini Süre:1m 0s

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