Ohm's Law

27 soru

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A field technician is testing a direct-current (DC) sensor module. What is the current flowing through the circuit when a potential difference of 90 V90\text{ V} is applied across a total circuit resistance of 15 kΩ15\text{ k}\Omega?

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Under an applied potential difference of 90 V90\text{ V}, a circuit having a resistance of 15 kΩ15\text{ k}\Omega conducts a current of milliamperes.
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Cevap

6 milliamperes (6 mA)
According to Ohm's law (I=VRI = \frac{V}{R}), dividing the 90 V90\text{ V} source by the 15,000 Ω15,000\ \Omega (15 kΩ15\text{ k}\Omega) total resistance yields 0.006 A0.006\text{ A}, which converts directly to 6 mA6\text{ mA}.

Adım Adım Çözüm

1
Identify known circuit quantities and convert resistance from kilohms to ohms.
V=90 VV = 90\text{ V} and R=15 kΩ=15×1,000 Ω=15,000 ΩR = 15\text{ k}\Omega = 15 \times 1,000\ \Omega = 15,000\ \Omega.
Standard electrical formulas require resistance in base units of ohms (Ω\Omega) to calculate current in amperes (A\text{A}).
2
Apply Ohm's law (I=VRI = \frac{V}{R}) to solve for the current in amperes.
I=90 V15,000 Ω=0.006 AI = \frac{90\text{ V}}{15,000\ \Omega} = 0.006\text{ A}.
Current is directly proportional to voltage and inversely proportional to resistance.
3
Convert current from amperes to milliamperes as requested by the statement.
0.006 A×1,000 mA/A=6 mA0.006\text{ A} \times 1,000\text{ mA/A} = 6\text{ mA}.
One milliampere equals one thousandth of an ampere (1 mA=10−3 A1\text{ mA} = 10^{-3}\text{ A}).

Anahtar Kavram

Ohm's Law (I=VRI = \frac{V}{R}) defines the proportional relationship between potential difference, current, and resistance in a direct-current circuit.
Tahmini Süre:45s
Soru 22Soru →

An automotive diagnostic technician connects an auxiliary relay coil to a 12 V12\text{ V} direct-current (DC) power supply. An ammeter placed in series measures a current of 150 mA150\text{ mA}. What is the electrical resistance of the relay coil?

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Cevap: 80 Ω80\ \Omega

Cevap

The electrical resistance of the relay coil is 80 Ω80\ \Omega.
According to Ohm's law, electrical resistance is calculated by dividing voltage by current (R=VIR = \frac{V}{I}). Converting 150 mA150\text{ mA} to 0.15 A0.15\text{ A} and dividing 12 V12\text{ V} by 0.15 A0.15\text{ A} gives 80 Ω80\ \Omega.

Adım Adım Çözüm

1
Convert the current from milliamperes (mA\text{mA}) to base units of amperes (A\text{A}).
I=150 mA=150×10−3 A=0.15 AI = 150\text{ mA} = 150 \times 10^{-3}\text{ A} = 0.15\text{ A}
Ohm's law requires values in standard SI base units (volts, amperes, and ohms) before performing calculations.
2
Rearrange Ohm's law (V=I×RV = I \times R) to solve for resistance (RR) and substitute the given values.
R=VI=12 V0.15 A=80 ΩR = \frac{V}{I} = \frac{12\text{ V}}{0.15\text{ A}} = 80\ \Omega
Resistance is equal to the potential difference divided by the current flowing through the component.

Anahtar Kavram

Ohm's Law states that resistance equals voltage divided by current (R=VIR = \frac{V}{I}), requiring current to be expressed in amperes.
Tahmini Süre:45s
Soru 23Soru →

A shipboard auxiliary alarm horn is connected across a 72 V72\text{ V} direct-current (DC) power rail. When activated, the horn draws a steady current of 120 mA120\text{ mA}. Based on Ohm's Law, what is the total electrical resistance of the horn circuit in ohms (Ω\Omega)?

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Cevap: 600

Cevap

The total electrical resistance of the horn circuit is 600 Ω600\ \Omega.
According to Ohm's Law, resistance equals voltage divided by current (R=VIR = \frac{V}{I}). Converting 120 mA120\text{ mA} to standard amperes gives 0.12 A0.12\text{ A}. Dividing 72 V72\text{ V} by 0.12 A0.12\text{ A} yields an electrical resistance of 600 Ω600\ \Omega.

Adım Adım Çözüm

1
Convert the current measurement from milliamperes to base amperes.
I=120 mA=0.12 AI = 120\text{ mA} = 0.12\text{ A}
Ohm's Law requires standard SI units (volts, amperes, and ohms) for direct substitution.
2
Rearrange Ohm's Law (V=I×RV = I \times R) to isolate resistance (RR).
R=VIR = \frac{V}{I}
The unknown quantity in this circuit problem is resistance.
3
Divide the applied voltage by the circuit current.
R=72 V0.12 A=600 ΩR = \frac{72\text{ V}}{0.12\text{ A}} = 600\ \Omega
Evaluating the division yields the equivalent circuit resistance in ohms.

Anahtar Kavram

Ohm's Law defines the proportional relationship between voltage, current, and resistance (R=VIR = \frac{V}{I}).
Tahmini Süre:45s
Soru 24Soru →

A technician is testing a telemetry circuit board and measures a steady direct current of 40 mA40\text{ mA} flowing through a 750 Ω750\ \Omega load resistor. What is the voltage drop across this resistor?

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Cevap: 30 V30\text{ V}

Cevap

30 V30\text{ V}
According to Ohm's Law (V=I×RV = I \times R), the voltage drop across a component is calculated by multiplying the current flowing through it by its resistance. Converting 40 mA40\text{ mA} to standard amperes gives 0.040 A0.040\text{ A}. Multiplying 0.040 A0.040\text{ A} by 750 Ω750\ \Omega yields a potential difference of 30 V30\text{ V}.

Adım Adım Çözüm

1
Convert current from milliamperes (mA) to base amperes (A)
I=40 mA=40×10−3 A=0.040 AI = 40\text{ mA} = 40 \times 10^{-3}\text{ A} = 0.040\text{ A}
Standard electrical calculations using Ohm's Law require base units of amperes, ohms, and volts.
2
Apply Ohm's Law to determine the potential difference (V=I×RV = I \times R)
V=0.040 A×750 Ω=30 VV = 0.040\text{ A} \times 750\ \Omega = 30\text{ V}
Voltage drop across a resistive element is directly proportional to the product of the current and resistance.

Anahtar Kavram

Ohm's Law (V=I×RV = I \times R) and metric unit conversion
Tahmini Süre:45s
Soru 25Soru →

An aircraft instrument panel contains a direct-current (DC) indicator circuit powered by a 120 V120\text{ V} source. What are the resulting circuit currents under each resistance condition? Fill in the blanks with the correct numerical values.

Aşağıdaki boşlukları doldurun

When connected to a 2.4 kΩ2.4\text{ k}\Omega resistor, the current is mA\text{mA}. If the resistance is increased to 4.8 kΩ4.8\text{ k}\Omega while maintaining constant voltage, the new current is mA\text{mA}.
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Cevap

The current with a 2.4 kΩ2.4\text{ k}\Omega resistor is 50 mA50\text{ mA}, and the current with a 4.8 kΩ4.8\text{ k}\Omega resistor is 25 mA25\text{ mA}.
According to Ohm's Law (I=VRI = \frac{V}{R}), converting 2.4 kΩ2.4\text{ k}\Omega to 2400 Ω2400\ \Omega yields an initial current of 120 V2400 Ω=0.05 A=50 mA\frac{120\text{ V}}{2400\ \Omega} = 0.05\text{ A} = 50\text{ mA}. When the resistance doubles to 4.8 kΩ4.8\text{ k}\Omega (4800 Ω4800\ \Omega) with constant voltage, the current is halved to 25 mA25\text{ mA}.

Adım Adım Çözüm

1
Convert the first resistance value from kilohms to ohms and apply Ohm's Law to calculate the initial current
R1=2.4 kΩ=2400 ΩR_1 = 2.4\text{ k}\Omega = 2400\ \Omega; I1=VR1=120 V2400 Ω=0.05 A=50 mAI_1 = \frac{V}{R_1} = \frac{120\text{ V}}{2400\ \Omega} = 0.05\text{ A} = 50\text{ mA}
Ohm's Law states that current equals voltage divided by resistance (I=VRI = \frac{V}{R}).
2
Convert the second resistance value or apply the principle of inverse proportionality to find the new current
R2=4.8 kΩ=4800 ΩR_2 = 4.8\text{ k}\Omega = 4800\ \Omega; I2=120 V4800 Ω=0.025 A=25 mAI_2 = \frac{120\text{ V}}{4800\ \Omega} = 0.025\text{ A} = 25\text{ mA} (or since resistance doubled at constant voltage, current halved: 50 mA2=25 mA\frac{50\text{ mA}}{2} = 25\text{ mA})
Current is inversely proportional to resistance when voltage remains constant.

Anahtar Kavram

Ohm's Law (I=VRI = \frac{V}{R}) and inverse proportionality between current and resistance at constant voltage
Tahmini Süre:45s
Soru 26Soru →

A radar transceiver module operates on a 45 V45\text{ V} direct-current (DC) power line. When the module is active, a series ammeter registers a current of 15 mA15\text{ mA}. What is the total electrical resistance of the module?

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Cevap: 3 kΩ3\text{ k}\Omega

Cevap

3 kΩ3\text{ k}\Omega (or 3,000 Ω3,000\ \Omega)
According to Ohm's Law, resistance is the quotient of voltage divided by current (R=VIR = \frac{V}{I}). Converting 15 mA15\text{ mA} to standard units gives 0.015 A0.015\text{ A}. Dividing the 45 V45\text{ V} potential difference by 0.015 A0.015\text{ A} results in 3,000 Ω3,000\ \Omega, which is equivalent to 3 kΩ3\text{ k}\Omega.

Adım Adım Çözüm

1
Convert the current measurement from milliamperes to base amperes.
I=15 mA=15×10−3 A=0.015 AI = 15\text{ mA} = 15 \times 10^{-3}\text{ A} = 0.015\text{ A}
Ohm's Law calculations require current to be expressed in standard SI units (amperes) to yield resistance in ohms.
2
Rearrange Ohm's Law (V=I×RV = I \times R) to solve for resistance (RR).
R=VIR = \frac{V}{I}
Isolating the unknown variable allows direct substitution of known circuit values.
3
Substitute the voltage and current values into the rearranged formula.
R=45 V0.015 A=3,000 Ω=3 kΩR = \frac{45\text{ V}}{0.015\text{ A}} = 3,000\ \Omega = 3\text{ k}\Omega
Dividing the potential difference by the current yields the total circuit resistance.

Anahtar Kavram

Ohm's Law defines the fundamental linear relationship between voltage, current, and resistance (V=I×RV = I \times R).
Tahmini Süre:45s
Soru 27Soru →

An avionics technician is troubleshooting a direct-current (DC) audio preamplifier circuit. The circuit is powered by an 18 V18\text{ V} DC source and draws a steady current of 2.5 mA2.5\text{ mA}. What is the total resistance of the circuit in kilohms (kΩ\text{k}\Omega)?

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Cevap: 7.2

Cevap

7.2 kΩ
According to Ohm's Law, resistance is determined by dividing voltage by current (R=VIR = \frac{V}{I}). Converting 2.5 mA2.5\text{ mA} to 0.0025 A0.0025\text{ A} and dividing 18 V18\text{ V} by 0.0025 A0.0025\text{ A} yields 7200 Ω7200\ \Omega, which equals 7.2 kΩ7.2\text{ k}\Omega.

Adım Adım Çözüm

1
Convert the current measurement from milliamperes (mA) to base amperes (A)
I=2.5 mA=0.0025 AI = 2.5\text{ mA} = 0.0025\text{ A}
Ohm's Law formulas require electrical quantities to be in standard base units (volts, amperes, and ohms) before computation.
2
Apply Ohm's Law rearranged to solve for resistance (R=VIR = \frac{V}{I})
R=18 V0.0025 A=7200 ΩR = \frac{18\text{ V}}{0.0025\text{ A}} = 7200\ \Omega
Resistance equals the electromotive force divided by the resulting current flow.
3
Convert the calculated resistance from ohms (Ω) to kilohms (kΩ)
R=7200 Ω1000 Ω/kΩ=7.2 kΩR = \frac{7200\ \Omega}{1000\ \Omega/\text{k}\Omega} = 7.2\text{ k}\Omega
The question specifically requests the final numerical value in kilohms.

Anahtar Kavram

Ohm's Law (R=VIR = \frac{V}{I}) with metric prefix conversion (1 mA=10−3 A1\text{ mA} = 10^{-3}\text{ A} and 1 kΩ=103 Ω1\text{ k}\Omega = 10^{3}\ \Omega)
Tahmini Süre:45s
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