Fundamental and Derived Units

18 soru

Soru 1Soru

The derived SI unit of force is the newton (N\text{N}), which can be expressed in terms of fundamental SI base units as kgmsx\text{kg}\cdot\text{m}\cdot\text{s}^{x}. What is the numerical value of the exponent xx?

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Cevap: -2

Cevap

The numerical value of the exponent xx for time in the base SI expression of the newton is 2-2.
Force is defined by Newton's second law as mass times acceleration (F=maF = ma). In SI fundamental units, mass is measured in kilograms (kg\text{kg}) and acceleration in meters per second squared (ms2\text{m}\cdot\text{s}^{-2}). Combining these yields 1 N=1 kgms2\text{1\ N} = \text{1\ kg}\cdot\text{m}\cdot\text{s}^{-2}. Therefore, the power of time in seconds (xx) is 2-2.

Adım Adım Çözüm

1
Identify the relationship between force and fundamental quantities
Force is defined as mass multiplied by acceleration (F=maF = ma)
This relates force to fundamental quantities of mass, length, and time.
2
Substitute the SI base units of mass and acceleration
Mass unit is kg\text{kg}; acceleration unit is ms2\text{m}\cdot\text{s}^{-2}
Kilogram, meter, and second are standard fundamental SI units.
3
Determine the exponent of seconds
The combined base unit expression is kgms2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}, giving x=2x = -2
Equating the powers of seconds gives x=2x = -2.

Anahtar Kavram

Expressing derived units in terms of fundamental SI base units
Soru 2Soru

The derived SI unit of electric potential, the volt (V\text{V}), can be expressed in terms of fundamental SI base units as kgambscAd\text{kg}^a \cdot \text{m}^b \cdot \text{s}^c \cdot \text{A}^d. What is the value of the exponent cc?

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Cevap: -3

Cevap

The exponent cc corresponding to the base unit second (s\text{s}) is 3-3.
Electric potential difference (VV) is defined as work (WW) per unit charge (QQ). In terms of SI base units, work has units of kgm2s2\text{kg} \cdot \text{m}^2 \cdot \text{s}^{-2} and charge has units of As\text{A} \cdot \text{s}. Dividing work by charge gives kgm2s2As=kg1m2s3A1\frac{\text{kg} \cdot \text{m}^2 \cdot \text{s}^{-2}}{\text{A} \cdot \text{s}} = \text{kg}^1 \cdot \text{m}^2 \cdot \text{s}^{-3} \cdot \text{A}^{-1}. Equating this to kgambscAd\text{kg}^a \cdot \text{m}^b \cdot \text{s}^c \cdot \text{A}^d yields c=3c = -3.

Adım Adım Çözüm

1
Relate electric potential to work and charge
1 V=1 J1 C\text{1 V} = \frac{\text{1 J}}{\text{1 C}}
Electric potential difference is defined as work done per unit electric charge.
2
Break down Joules into base SI units
1 J=1 Nm=(1 kgms2)m=1 kgm2s2\text{1 J} = \text{1 N} \cdot \text{m} = (\text{1 kg} \cdot \text{m} \cdot \text{s}^{-2}) \cdot \text{m} = \text{1 kg} \cdot \text{m}^2 \cdot \text{s}^{-2}
Work is force multiplied by displacement, and force is mass multiplied by acceleration.
3
Break down Coulombs into base SI units
1 C=1 As\text{1 C} = \text{1 A} \cdot \text{s}
Electric charge is electric current multiplied by time.
4
Substitute base unit expressions into the ratio for electric potential
1 V=1 kgm2s21 As=1 kg1m2s3A1\text{1 V} = \frac{\text{1 kg} \cdot \text{m}^2 \cdot \text{s}^{-2}}{\text{1 A} \cdot \text{s}} = \text{1 kg}^1 \cdot \text{m}^2 \cdot \text{s}^{-3} \cdot \text{A}^{-1}
Combining powers of base units yields the complete fundamental representation.
5
Determine the exponent value cc
c=3c = -3
Comparing kgambscAd\text{kg}^a \cdot \text{m}^b \cdot \text{s}^c \cdot \text{A}^d to kg1m2s3A1\text{kg}^1 \cdot \text{m}^2 \cdot \text{s}^{-3} \cdot \text{A}^{-1} shows that the exponent of s\text{s} is 3-3.

Anahtar Kavram

Expressing derived units in terms of fundamental SI base units
Soru 3Soru

Match each derived SI unit listed on the left with its corresponding fundamental (base) SI unit representation on the right.

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Öğeler

Joule (J\text{J})
Pascal (Pa\text{Pa})
Watt (W\text{W})
Newton (N\text{N})

Eşleşmeler

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Cevap

Joule (J\text{J}) matches kgm2s2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}; Pascal (Pa\text{Pa}) matches kgm1s2\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}; Watt (W\text{W}) matches kgm2s3\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}; Newton (N\text{N}) matches kgms2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}.
Each derived unit is systematically expressed in terms of the fundamental SI units of mass (kg), length (m), and time (s) by substituting definitions: Newton is kgms2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}, Joule is kgm2s2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}, Pascal is kgm1s2\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}, and Watt is kgm2s3\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}.

Adım Adım Çözüm

1
Express Newton (N) in fundamental units
Force=mass×acceleration1 N=1 kgms2\text{Force} = \text{mass} \times \text{acceleration} \Rightarrow 1\text{ N} = 1\text{ kg}\cdot\text{m}\cdot\text{s}^{-2}
Force is defined as mass multiplied by acceleration.
2
Express Joule (J) in fundamental units
Work=Force×distance1 J=(kgms2)×m=1 kgm2s2\text{Work} = \text{Force} \times \text{distance} \Rightarrow 1\text{ J} = (\text{kg}\cdot\text{m}\cdot\text{s}^{-2}) \times \text{m} = 1\text{ kg}\cdot\text{m}^2\cdot\text{s}^{-2}
Work done is force multiplied by displacement in the direction of the force.
3
Express Pascal (Pa) in fundamental units
Pressure=ForceArea1 Pa=kgms2m2=1 kgm1s2\text{Pressure} = \frac{\text{Force}}{\text{Area}} \Rightarrow 1\text{ Pa} = \frac{\text{kg}\cdot\text{m}\cdot\text{s}^{-2}}{\text{m}^2} = 1\text{ kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}
Pressure is defined as force applied perpendicular to a surface per unit area.
4
Express Watt (W) in fundamental units
Power=Worktime1 W=kgm2s2s=1 kgm2s3\text{Power} = \frac{\text{Work}}{\text{time}} \Rightarrow 1\text{ W} = \frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}}{\text{s}} = 1\text{ kg}\cdot\text{m}^2\cdot\text{s}^{-3}
Power is the rate at which work is done or energy is transferred.

Anahtar Kavram

Expressing derived SI units in terms of base SI fundamental units
Soru 4Soru

Which of the following correctly expresses the derived SI unit of power, the watt (W\text{W}), in terms of fundamental SI base units?

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Cevap: kgm2s3\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}

Cevap

The watt (W\text{W}) expressed in fundamental SI base units is kgm2s3\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}.
Power is defined as energy transferred or work done per unit time (P=Wt\text{P} = \frac{W}{t}). Work is force times distance (Nm=kgm2s2\text{N}\cdot\text{m} = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}). Dividing work by time (s\text{s}) yields kgm2s3\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}.

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1
Recall the defining formula for power
Power=WorkTime=Force×DisplacementTime\text{Power} = \frac{\text{Work}}{\text{Time}} = \frac{\text{Force} \times \text{Displacement}}{\text{Time}}
Relating the derived quantity to simpler mechanical quantities.
2
Break down force into fundamental base units using Newton's second law (F=maF = ma)
Unit of Force (Newton)=kgms2\text{Unit of Force (Newton)} = \text{kg}\cdot\text{m}\cdot\text{s}^{-2}
Mass is measured in kilograms (kg\text{kg}), acceleration in meters per second squared (ms2\text{m}\cdot\text{s}^{-2}).
3
Express work in fundamental base units
Unit of Work (Joule)=(kgms2)×m=kgm2s2\text{Unit of Work (Joule)} = (\text{kg}\cdot\text{m}\cdot\text{s}^{-2}) \times \text{m} = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}
Work is force multiplied by distance.
4
Divide the unit of work by the unit of time (seconds)
Unit of Power (Watt)=kgm2s2s=kgm2s3\text{Unit of Power (Watt)} = \frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}}{\text{s}} = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}
Dividing by s\text{s} decreases the exponent of seconds by 1.

Anahtar Kavram

Expressing derived SI units in terms of fundamental SI base units
Tahmini Süre:1m 0s
Soru 5Soru

The derived SI unit of dynamic viscosity, the pascal-second (Pas\text{Pa}\cdot\text{s}), can be expressed in fundamental SI base units as kgambsc\text{kg}^a \cdot \text{m}^b \cdot \text{s}^c. Determine the numerical value of the exponent of length, bb.

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Cevap: -1

Cevap

The numerical value of the exponent of length bb is 1-1.
Dynamic viscosity is measured in pascal-seconds (Pas\text{Pa}\cdot\text{s}). Substituting 1 Pa=1 N/m2=1 kgm1s21\text{ Pa} = 1\text{ N/m}^2 = 1\text{ kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2} into the formula gives 1 Pas=1 kg1m1s11\text{ Pa}\cdot\text{s} = 1\text{ kg}^1 \cdot \text{m}^{-1} \cdot \text{s}^{-1}. Comparing this with kgambsc\text{kg}^a \cdot \text{m}^b \cdot \text{s}^c, the exponent of length (meters) is b=1b = -1.

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1
Express the newton in base SI units using F=maF = ma.
N=kgms2\text{N} = \text{kg}\cdot\text{m}\cdot\text{s}^{-2}.
Force is the product of mass and acceleration.
2
Derive the SI base unit expression for pressure (pascal, Pa\text{Pa}).
Pa=Nm2=kgms2m2=kgm1s2\text{Pa} = \frac{\text{N}}{\text{m}^2} = \frac{\text{kg}\cdot\text{m}\cdot\text{s}^{-2}}{\text{m}^2} = \text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}.
Pressure is defined as force per unit area.
3
Multiply the base unit expression of pressure by seconds.
Pas=(kgm1s2)s1=kg1m1s1\text{Pa}\cdot\text{s} = (\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}) \cdot \text{s}^1 = \text{kg}^1 \cdot \text{m}^{-1} \cdot \text{s}^{-1}.
Dynamic viscosity is measured in pascal-seconds.
4
Extract the exponent of length (bb) corresponding to the meter unit.
b=1b = -1.
The power of meters (m\text{m}) in kg1m1s1\text{kg}^1 \cdot \text{m}^{-1} \cdot \text{s}^{-1} is 1-1.

Anahtar Kavram

Deriving base SI units for derived physical quantities
Tahmini Süre:1m 30s
Soru 6Soru

The derived SI unit of electrical resistance is the ohm (Ω\Omega). Which of the following correctly expresses the ohm strictly in terms of fundamental SI base units?

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Cevap: kgm2s3A2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-2}

Cevap

kgm2s3A2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-2}
Resistance is defined by Ohm's Law as voltage divided by current (R=V/IR = V / I). Voltage is work done per unit charge (V=W/QV = W / Q), and charge is current multiplied by time (Q=ItQ = I \cdot t). Substituting the unit of work (kgm2s2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}) gives R=kgm2s2A2s=kgm2s3A2R = \frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}}{\text{A}^2\cdot\text{s}} = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-2}.

Adım Adım Çözüm

1
Relate resistance to potential difference and current using Ohm's Law.
R=VIR = \frac{V}{I}
Resistance is defined as the ratio of potential difference to electric current.
2
Express electric potential difference (VV) in terms of work (WW) and charge (QQ), where Q=ItQ = I \cdot t.
V=WIt    R=WI2tV = \frac{W}{I \cdot t} \implies R = \frac{W}{I^2 \cdot t}
Electric potential difference is work done per unit charge, and electric charge is current multiplied by time.
3
Break down work (W=Force×distanceW = \text{Force} \times \text{distance}) into base SI units.
Unit of Work = kgm2s2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}
Force is mass times acceleration (kgms2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}), so work is kgm2s2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}.
4
Substitute all base units into the resistance formula.
Unit of R=kgm2s2A2s=kgm2s3A2R = \frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}}{\text{A}^2 \cdot \text{s}} = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-2}
Combining powers of base units yields the complete fundamental SI base unit expression for the ohm.

Anahtar Kavram

Derivation of SI base units from defining formulas of physical quantities
Soru 7Soru

Match each physical quantity listed on the left with its corresponding expression in fundamental SI base units on the right.

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Öğeler

Pressure
Surface Tension
Specific Heat Capacity
Electric Capacitance

Eşleşmeler

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Cevap

Pressure matches with kgm1s2\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}, Surface Tension matches with kgs2\text{kg}\cdot\text{s}^{-2}, Specific Heat Capacity matches with m2s2K1\text{m}^2\cdot\text{s}^{-2}\cdot\text{K}^{-1}, and Electric Capacitance matches with kg1m2s4A2\text{kg}^{-1}\cdot\text{m}^{-2}\cdot\text{s}^4\cdot\text{A}^2.
Each quantity on the left is matched correctly to its fundamental SI base unit equivalent derived directly from its defining physical formula.

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1
Derive base SI units for Pressure
P=FA=kgms2m2=kgm1s2P = \frac{F}{A} = \frac{\text{kg}\cdot\text{m}\cdot\text{s}^{-2}}{\text{m}^2} = \text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}
Pressure is force per unit area.
2
Derive base SI units for Surface Tension
γ=FL=kgms2m=kgs2\gamma = \frac{F}{L} = \frac{\text{kg}\cdot\text{m}\cdot\text{s}^{-2}}{\text{m}} = \text{kg}\cdot\text{s}^{-2}
Surface tension is force per unit length.
3
Derive base SI units for Specific Heat Capacity
c=QmΔT=kgm2s2kgK=m2s2K1c = \frac{Q}{m\Delta T} = \frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}}{\text{kg}\cdot\text{K}} = \text{m}^2\cdot\text{s}^{-2}\cdot\text{K}^{-1}
Specific heat capacity is thermal energy per unit mass per kelvin.
4
Derive base SI units for Electric Capacitance
C=QV=Askgm2s3A1=kg1m2s4A2C = \frac{Q}{V} = \frac{\text{A}\cdot\text{s}}{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-1}} = \text{kg}^{-1}\cdot\text{m}^{-2}\cdot\text{s}^4\cdot\text{A}^2
Capacitance is electric charge divided by electric potential difference.

Anahtar Kavram

Expressing derived SI units in terms of fundamental base SI units
Soru 8Soru

In the International System of Units (SI), physical quantities are categorized as either fundamental or derived. Which of the following is a fundamental SI base unit?

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Cevap: Kelvin

Cevap

Kelvin is the fundamental SI base unit.
The kelvin is the standard SI base unit for measuring thermodynamic temperature and is one of the seven defined fundamental units.

Adım Adım Çözüm

1
Identify the seven SI fundamental (base) units
The seven fundamental SI base units are the meter (m), kilogram (kg), second (s), ampere (A), kelvin (K), mole (mol), and candela (cd).
Fundamental units are basic units that are independent of one another and cannot be expressed in terms of other units.
2
Compare the given options against the set of fundamental units
Among Joule, Kelvin, Pascal, and Watt, only Kelvin is in the list of fundamental SI base units.
Joule, Pascal, and Watt are all derived units defined by combinations of base units.

Anahtar Kavram

Fundamental SI Base Units
Tahmini Süre:35s
Soru 9Soru

Match each physical quantity on the left with its corresponding SI unit expressed in terms of fundamental (base) units on the right.

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Öğeler

Frequency
Electric charge
Mass density
Acceleration

Eşleşmeler

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Cevap

Frequency matches s1\text{s}^{-1}, Electric charge matches As\text{A}\cdot\text{s}, Mass density matches kgm3\text{kg}\cdot\text{m}^{-3}, and Acceleration matches ms2\text{m}\cdot\text{s}^{-2}.
Frequency (f=1/Tf = 1/T) is expressed in reciprocal seconds (s1\text{s}^{-1}). Electric charge (Q=ItQ = I \cdot t) is current times time, giving As\text{A}\cdot\text{s}. Mass density (ρ=m/V\rho = m/V) is mass per volume, giving kgm3\text{kg}\cdot\text{m}^{-3}. Acceleration (a=Δv/Δta = \Delta v / \Delta t) is rate of velocity change, giving ms2\text{m}\cdot\text{s}^{-2}.

Adım Adım Çözüm

1
Identify the defining formula for each physical quantity
Frequency f=1Tf = \frac{1}{T}, Charge Q=ItQ = I \cdot t, Density ρ=mV\rho = \frac{m}{V}, Acceleration a=ΔvΔta = \frac{\Delta v}{\Delta t}.
Relating derived quantities to their defining equations allows reduction into fundamental quantities.
2
Substitute the SI base units for mass (kg\text{kg}), length (m\text{m}), time (s\text{s}), and current (A\text{A})
Frequency: s1\text{s}^{-1}; Charge: As\text{A}\cdot\text{s}; Density: kgm3=kgm3\frac{\text{kg}}{\text{m}^3} = \text{kg}\cdot\text{m}^{-3}; Acceleration: m/ss=ms2\frac{\text{m/s}}{\text{s}} = \text{m}\cdot\text{s}^{-2}.
This expresses each derived unit strictly in terms of fundamental SI units.
3
Match each physical quantity to its calculated base unit representation
Frequency s1\rightarrow \text{s}^{-1}, Electric charge As\rightarrow \text{A}\cdot\text{s}, Mass density kgm3\rightarrow \text{kg}\cdot\text{m}^{-3}, Acceleration ms2\rightarrow \text{m}\cdot\text{s}^{-2}.
Completes the pairing verification.

Anahtar Kavram

Expressing derived physical quantities in terms of SI fundamental (base) units
Tahmini Süre:45s
Soru 10Soru

Match each physical quantity listed on the left with its corresponding SI unit expressed strictly in terms of fundamental (base) units on the right.

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Öğeler

Electric permittivity of free space (ε0\varepsilon_0)
Magnetic permeability of free space (μ0\mu_0)
Thermal conductivity (kk)
Specific heat capacity (cc)

Eşleşmeler

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Cevap

Electric permittivity of free space maps to kg1m3s4A2\text{kg}^{-1}\cdot\text{m}^{-3}\cdot\text{s}^4\cdot\text{A}^2, Magnetic permeability of free space maps to kgms2A2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}\cdot\text{A}^{-2}, Thermal conductivity maps to kgms3K1\text{kg}\cdot\text{m}\cdot\text{s}^{-3}\cdot\text{K}^{-1}, and Specific heat capacity maps to m2s2K1\text{m}^2\cdot\text{s}^{-2}\cdot\text{K}^{-1}.
Each physical quantity is matched to its exact fundamental unit expression obtained by substituting basic formulas into SI base units (kg\text{kg}, m\text{m}, s\text{s}, A\text{A}, K\text{K}). Electric permittivity resolves to kg1m3s4A2\text{kg}^{-1}\cdot\text{m}^{-3}\cdot\text{s}^4\cdot\text{A}^2, magnetic permeability resolves to kgms2A2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}\cdot\text{A}^{-2}, thermal conductivity resolves to kgms3K1\text{kg}\cdot\text{m}\cdot\text{s}^{-3}\cdot\text{K}^{-1}, and specific heat capacity resolves to m2s2K1\text{m}^2\cdot\text{s}^{-2}\cdot\text{K}^{-1}.

Adım Adım Çözüm

1
Derive the base SI units for Electric permittivity of free space (ε0\varepsilon_0).
From Coulomb's Law, F=q1q24πε0r2    ε0=q1q24πFr2F = \frac{q_1 q_2}{4\pi \varepsilon_0 r^2} \implies \varepsilon_0 = \frac{q_1 q_2}{4\pi F r^2}. Expressing terms in SI fundamental units: charge q=Asq = \text{A}\cdot\text{s}, force F=kgms2F = \text{kg}\cdot\text{m}\cdot\text{s}^{-2}, distance r=mr = \text{m}. Thus, [ε0]=(As)2(kgms2)m2=kg1m3s4A2[\varepsilon_0] = \frac{(\text{A}\cdot\text{s})^2}{(\text{kg}\cdot\text{m}\cdot\text{s}^{-2})\cdot\text{m}^2} = \text{kg}^{-1}\cdot\text{m}^{-3}\cdot\text{s}^4\cdot\text{A}^2.
Relating derived electromagnetic quantities to fundamental SI units via governing physical equations.
2
Derive the base SI units for Magnetic permeability of free space (μ0\mu_0).
From the force per unit length between parallel current-carrying conductors, FL=μ0I1I22πr    μ0=2πFrI1I2L\frac{F}{L} = \frac{\mu_0 I_1 I_2}{2\pi r} \implies \mu_0 = \frac{2\pi F r}{I_1 I_2 L}. Units: [μ0]=(kgms2)mA2m=kgms2A2[\mu_0] = \frac{(\text{kg}\cdot\text{m}\cdot\text{s}^{-2})\cdot\text{m}}{\text{A}^2\cdot\text{m}} = \text{kg}\cdot\text{m}\cdot\text{s}^{-2}\cdot\text{A}^{-2}.
Using Ampère's force law to solve for magnetic permeability in base units.
3
Derive the base SI units for Thermal conductivity (kk).
From Fourier's Law of Heat Conduction, Qt=kAΔTΔx    k=QΔxtAΔT\frac{Q}{t} = k A \frac{\Delta T}{\Delta x} \implies k = \frac{Q \cdot \Delta x}{t A \Delta T}. Heat energy Q=kgm2s2Q = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}, time t=st = \text{s}, area A=m2A = \text{m}^2, thickness Δx=m\Delta x = \text{m}, temperature difference ΔT=K\Delta T = \text{K}. Thus, [k]=(kgm2s2)msm2K=kgms3K1[k] = \frac{(\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2})\cdot\text{m}}{\text{s}\cdot\text{m}^2\cdot\text{K}} = \text{kg}\cdot\text{m}\cdot\text{s}^{-3}\cdot\text{K}^{-1}.
Connecting thermal conduction equations to fundamental mechanics and thermodynamic units.
4
Derive the base SI units for Specific heat capacity (cc).
From Q=mcΔT    c=QmΔTQ = m c \Delta T \implies c = \frac{Q}{m \Delta T}. Units: [c]=kgm2s2kgK=m2s2K1[c] = \frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}}{\text{kg}\cdot\text{K}} = \text{m}^2\cdot\text{s}^{-2}\cdot\text{K}^{-1}.
Applying the defining equation of heat capacity to reduce the unit to fundamental base units.

Anahtar Kavram

Derivation of complex derived SI units from fundamental base units using fundamental physical laws.
Soru 11Soru

Match each physical quantity to its correct SI unit.

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Öğeler

Electric current
Force
Thermodynamic temperature
Energy

Eşleşmeler

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Cevap

Electric current matches Ampere (A); Force matches Newton (N); Thermodynamic temperature matches Kelvin (K); Energy matches Joule (J).
Electric current and thermodynamic temperature are fundamental quantities measured in amperes and kelvins respectively. Force and energy are derived quantities whose units (newton and joule) are combinations of base SI units.

Adım Adım Çözüm

1
Identify fundamental physical quantities and their base SI units.
Electric current is measured in amperes (A), and thermodynamic temperature is measured in kelvins (K). Both are fundamental SI units.
Fundamental units are basic units that are defined independently of other quantities.
2
Identify derived physical quantities and their derived SI units.
Force is measured in newtons (N), and energy is measured in joules (J). Both are derived SI units.
Derived units are obtained by combining fundamental SI base units according to physical equations.

Anahtar Kavram

Classification of fundamental and derived SI units
Tahmini Süre:45s
Soru 12Soru

According to Newton's law of universal gravitation, the gravitational force FF between two masses m1m_1 and m2m_2 separated by a distance rr is given by F=Gm1m2r2F = \frac{G m_1 m_2}{r^2}. Which of the following correctly expresses the derived SI unit of the universal gravitational constant, GG, in terms of fundamental (base) units?

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Cevap: kg1m3s2\text{kg}^{-1}\cdot\text{m}^3\cdot\text{s}^{-2}

Cevap

The SI unit of the universal gravitational constant GG expressed in fundamental base units is kg1m3s2\text{kg}^{-1}\cdot\text{m}^3\cdot\text{s}^{-2}.
The expression kg1m3s2\text{kg}^{-1}\cdot\text{m}^3\cdot\text{s}^{-2} is correct because rearranging F=Gm1m2r2F = \frac{G m_1 m_2}{r^2} yields G=Fr2m1m2G = \frac{F r^2}{m_1 m_2}. Replacing FF with its base equivalent kgms2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}, rr with m\text{m}, and m1,m2m_1, m_2 with kg\text{kg} gives (kgms2)m2kg2=kg1m3s2\frac{(\text{kg}\cdot\text{m}\cdot\text{s}^{-2})\cdot\text{m}^2}{\text{kg}^2} = \text{kg}^{-1}\cdot\text{m}^3\cdot\text{s}^{-2}.

Adım Adım Çözüm

1
Rearrange the gravitational formula to solve for GG
G=Fr2m1m2G = \frac{F \cdot r^2}{m_1 \cdot m_2}
To express the unit of GG, we need it in terms of quantities with known units.
2
Substitute the SI unit for force in fundamental base units
\text{Unit of } F = \text{N} = \text{kg}\cdot\text{m}\cdot\text{s}^{-2}
Force is mass times acceleration (F=maF = ma), so its base unit is kgms2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}.
3
Substitute all base units into the formula for GG
\text{Unit of } G = \frac{(\text{kg}\cdot\text{m}\cdot\text{s}^{-2}) \cdot \text{m}^2}{\text{kg} \cdot \text{kg}} = \frac{\text{kg}\cdot\text{m}^3\cdot\text{s}^{-2}}{\text{kg}^2}
Combining length terms (mm2=m3\text{m} \cdot \text{m}^2 = \text{m}^3) and mass terms in the denominator.
4
Simplify the mass exponent using laws of indices
\text{Unit of } G = \text{kg}^{1 - 2}\cdot\text{m}^3\cdot\text{s}^{-2} = \text{kg}^{-1}\cdot\text{m}^3\cdot\text{s}^{-2}
Dividing by kg2\text{kg}^2 subtracts 2 from the mass exponent.

Anahtar Kavram

Derivation of Derived Units in Base SI Units
Tahmini Süre:1m 15s
Soru 13Soru

Pair each physical quantity in List I with its equivalent SI unit expressed purely in terms of fundamental base units in List II.

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Öğeler

Electric Charge
Linear Momentum
Young's Modulus
Magnetic Flux Density

Eşleşmeler

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Cevap

Electric Charge matches As\text{A}\cdot\text{s}; Linear Momentum matches kgms1\text{kg}\cdot\text{m}\cdot\text{s}^{-1}; Young's Modulus matches kgm1s2\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}; Magnetic Flux Density matches kgs2A1\text{kg}\cdot\text{s}^{-2}\cdot\text{A}^{-1}.
Each physical quantity is resolved to fundamental SI base units using defining equations: Electric charge (Q=ItQ=It) yields As\text{A}\cdot\text{s}, linear momentum (p=mvp=mv) yields kgms1\text{kg}\cdot\text{m}\cdot\text{s}^{-1}, Young's modulus (stress/strain) yields kgm1s2\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}, and magnetic flux density (B=FILB=\frac{F}{IL}) yields kgs2A1\text{kg}\cdot\text{s}^{-2}\cdot\text{A}^{-1}.

Adım Adım Çözüm

1
Derive base units for Electric Charge
As\text{A}\cdot\text{s}
From Q=ItQ = I t, electric current has the fundamental unit ampere (A) and time has the fundamental unit second (s).
2
Derive base units for Linear Momentum
kgms1\text{kg}\cdot\text{m}\cdot\text{s}^{-1}
From p=mvp = m v, mass is in kilograms (kg) and velocity is in meters per second (m/s).
3
Derive base units for Young's Modulus
kgm1s2\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}
Tensile strain is dimensionless. Tensile stress is force per area: Nm2=kgms2m2=kgm1s2\frac{\text{N}}{\text{m}^2} = \frac{\text{kg}\cdot\text{m}\cdot\text{s}^{-2}}{\text{m}^2} = \text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}.
4
Derive base units for Magnetic Flux Density
kgs2A1\text{kg}\cdot\text{s}^{-2}\cdot\text{A}^{-1}
From magnetic force F=ILBF = I L B, solving for B=FILB = \frac{F}{I L} gives kgms2Am=kgs2A1\frac{\text{kg}\cdot\text{m}\cdot\text{s}^{-2}}{\text{A}\cdot\text{m}} = \text{kg}\cdot\text{s}^{-2}\cdot\text{A}^{-1}.

Anahtar Kavram

Expressing derived physical quantities in terms of fundamental SI base units
Soru 14Soru

Match each derived physical quantity in Column I with its equivalent SI unit expressed in terms of fundamental (base) units in Column II.

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Öğeler

Gravitational Potential
Electrical Conductance
Self-Inductance
Impulse

Eşleşmeler

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Cevap

Gravitational Potential matches m2s2\text{m}^2\cdot\text{s}^{-2}; Electrical Conductance matches kg1m2s3A2\text{kg}^{-1}\cdot\text{m}^{-2}\cdot\text{s}^3\cdot\text{A}^2; Self-Inductance matches kgm2s2A2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}\cdot\text{A}^{-2}; Impulse matches kgms1\text{kg}\cdot\text{m}\cdot\text{s}^{-1}.
Each derived unit is systematically expressed in terms of the fundamental SI base units (kilogram, meter, second, ampere) by substituting defining formulas. Gravitational potential is energy per unit mass (Jkg1=m2s2\text{J}\cdot\text{kg}^{-1} = \text{m}^2\cdot\text{s}^{-2}). Electrical conductance is reciprocal resistance (Siemens =AV1=kg1m2s3A2= \text{A}\cdot\text{V}^{-1} = \text{kg}^{-1}\cdot\text{m}^{-2}\cdot\text{s}^3\cdot\text{A}^2). Self-Inductance is electromotive force per rate of change of current (Henry =VsA1=kgm2s2A2= \text{V}\cdot\text{s}\cdot\text{A}^{-1} = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}\cdot\text{A}^{-2}). Impulse is force times time (Ns=kgms1\text{N}\cdot\text{s} = \text{kg}\cdot\text{m}\cdot\text{s}^{-1}).

Adım Adım Çözüm

1
Derive base units for Gravitational Potential
m2s2\text{m}^2\cdot\text{s}^{-2}
Gravitational potential is potential energy per unit mass (V=Epm=kgm2s2kgV = \frac{E_p}{m} = \frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}}{\text{kg}}).
2
Derive base units for Electrical Conductance
kg1m2s3A2\text{kg}^{-1}\cdot\text{m}^{-2}\cdot\text{s}^3\cdot\text{A}^2
Conductance is current divided by voltage (G=IV=Akgm2s3A1G = \frac{I}{V} = \frac{\text{A}}{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-1}}).
3
Derive base units for Self-Inductance
kgm2s2A2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}\cdot\text{A}^{-2}
Inductance is voltage multiplied by time divided by current (L=VtI=kgm2s3A1sAL = \frac{V \cdot t}{I} = \frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-1} \cdot \text{s}}{\text{A}}).
4
Derive base units for Impulse
kgms1\text{kg}\cdot\text{m}\cdot\text{s}^{-1}
Impulse is force multiplied by time (I=Ft=(kgms2)sI = F \cdot t = (\text{kg}\cdot\text{m}\cdot\text{s}^{-2}) \cdot \text{s}).

Anahtar Kavram

Break down derived physical quantities into fundamental SI quantities (mass in kg, length in m, time in s, electric current in A) using defining physical formulas.
Tahmini Süre:1m 30s
Soru 15Soru

Which of the following combinations of fundamental SI base units is equivalent to the volt (V\text{V}), the SI unit of electric potential difference?

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Cevap: kgm2s3A1\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-1}

Cevap

kgm2s3A1\text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-1}
Electric potential difference (VV) is defined as work done (WW) per unit charge (QQ), giving V=WQV = \frac{W}{Q}. In fundamental SI units, work is kgm2s2\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2} and electric charge is As\text{A}\cdot\text{s}. Dividing work by charge yields kgm2s2As=kgm2s3A1\frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}}{\text{A}\cdot\text{s}} = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-1}.

Adım Adım Çözüm

1
State the defining physical equation for electric potential difference.
V=WQV = \frac{W}{Q}, where VV is electric potential, WW is work done in joules, and QQ is electric charge in coulombs.
Electric potential difference is defined as work done per unit electric charge.
2
Express work (WW) in terms of fundamental SI base units.
W=Force×distance=(kgms2)×m=kgm2s2W = \text{Force} \times \text{distance} = (\text{kg}\cdot\text{m}\cdot\text{s}^{-2}) \times \text{m} = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}.
Work is the product of force and displacement, where force is mass times acceleration.
3
Express electric charge (QQ) in terms of fundamental SI base units.
Q=I×t=AsQ = I \times t = \text{A}\cdot\text{s}.
Electric charge is defined as electric current multiplied by time.
4
Divide the base units of work by the base units of electric charge.
V=kgm2s2As=kgm2s3A1V = \frac{\text{kg}\cdot\text{m}^2\cdot\text{s}^{-2}}{\text{A}\cdot\text{s}} = \text{kg}\cdot\text{m}^2\cdot\text{s}^{-3}\cdot\text{A}^{-1}.
Simplifying the exponents gives the equivalent combination of fundamental SI base units.

Anahtar Kavram

Expressing derived SI units in terms of fundamental (base) SI units.
Soru 16Soru

The derived SI unit of electric capacitance, the farad (F\text{F}), can be expressed in terms of fundamental SI base units as kgambscAd\text{kg}^a \cdot \text{m}^b \cdot \text{s}^c \cdot \text{A}^d. What is the numerical value of the sum of the exponents a+b+c+da + b + c + d?

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Cevap: 3

Cevap

The numerical value of the sum of the exponents a+b+c+da + b + c + d is 3.
The farad (F\text{F}), when resolved into fundamental SI base units, is kg1m2s4A2\text{kg}^{-1} \cdot \text{m}^{-2} \cdot \text{s}^4 \cdot \text{A}^2. Adding the exponents yields a=1a = -1, b=2b = -2, c=4c = 4, and d=2d = 2, giving a total sum of (1)+(2)+4+2=3(-1) + (-2) + 4 + 2 = 3.

Adım Adım Çözüm

1
Relate electric capacitance to fundamental physical quantities
Capacitance is defined as C=QVC = \frac{Q}{V}, where QQ is electric charge and VV is electric potential difference.
This fundamental relation connects capacitance to charge and energy per unit charge.
2
Express charge and potential difference in terms of SI base units
Electric charge QQ has base units As\text{A} \cdot \text{s}. Potential difference V=WorkQV = \frac{\text{Work}}{Q} has base units kgm2s2As=kgm2s3A1\frac{\text{kg} \cdot \text{m}^2 \cdot \text{s}^{-2}}{\text{A} \cdot \text{s}} = \text{kg} \cdot \text{m}^2 \cdot \text{s}^{-3} \cdot \text{A}^{-1}.
Work is force times distance (kgms2×m=kgm2s2\text{kg} \cdot \text{m} \cdot \text{s}^{-2} \times \text{m} = \text{kg} \cdot \text{m}^2 \cdot \text{s}^{-2}) and electric current is a fundamental base quantity.
3
Determine the base unit representation of the farad
The farad is expressed as Askgm2s3A1=kg1m2s4A2\frac{\text{A} \cdot \text{s}}{\text{kg} \cdot \text{m}^2 \cdot \text{s}^{-3} \cdot \text{A}^{-1}} = \text{kg}^{-1} \cdot \text{m}^{-2} \cdot \text{s}^4 \cdot \text{A}^2.
Dividing the unit of charge by the unit of potential difference yields the derived base unit expression.
4
Calculate the sum of the exponents
a+b+c+d=(1)+(2)+4+2=3a + b + c + d = (-1) + (-2) + 4 + 2 = 3.
Summing the powers corresponding to kilograms, meters, seconds, and amperes gives the final scalar value.

Anahtar Kavram

Expressing derived SI units in terms of fundamental SI base units
Soru 17Soru

The coefficient of dynamic viscosity η\eta of a fluid can be defined using Newton's formula for viscous flow, η=FAΔvΔx\eta = \frac{F}{A \frac{\Delta v}{\Delta x}}, where FF is the viscous drag force, AA is the contact surface area, and ΔvΔx\frac{\Delta v}{\Delta x} is the velocity gradient perpendicular to the flow. Which of the following combinations of fundamental SI base units is equivalent to the coefficient of dynamic viscosity?

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Cevap: kgm1s1\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-1}

Cevap

The coefficient of dynamic viscosity expressed in fundamental SI base units is kgm1s1\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-1}.
The unit of dynamic viscosity is derived from η=FA(Δv/Δx)\eta = \frac{F}{A (\Delta v / \Delta x)}. Substituting base units yields kgms2m2s1=kgm1s1\frac{\text{kg}\cdot\text{m}\cdot\text{s}^{-2}}{\text{m}^2 \cdot \text{s}^{-1}} = \text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-1}, which correctly represents the unit in base SI quantities.

Adım Adım Çözüm

1
Identify the fundamental SI base units for each quantity in the formula
Force FF has units kgms2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}; Area AA has units m2\text{m}^2; Velocity gradient ΔvΔx\frac{\Delta v}{\Delta x} has units ms1m=s1\frac{\text{m}\cdot\text{s}^{-1}}{\text{m}} = \text{s}^{-1}.
Decomposing derived physical quantities into SI base units is essential for dimensional reduction.
2
Substitute these fundamental units into the given formula for η\eta
Unit of η=kgms2m2s1\text{Unit of } \eta = \frac{\text{kg}\cdot\text{m}\cdot\text{s}^{-2}}{\text{m}^2 \cdot \text{s}^{-1}}.
Direct algebraic substitution yields the compound unit expression.
3
Simplify the powers of mass, length, and time
kg1m12s2(1)=kgm1s1\text{kg}^1 \cdot \text{m}^{1 - 2} \cdot \text{s}^{-2 - (-1)} = \text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-1}.
Applying exponent rules simplifies the expression to base units.

Anahtar Kavram

Expressing derived units in terms of fundamental SI base units (kilogram, meter, second)
Soru 18Soru

The force constant (stiffness) kk of a helical spring measures its resistance to elastic deformation and is defined by the relationship k=Fek = \frac{F}{e}, where FF represents the restoring force and ee represents the extension. Which of the following represents the SI unit of kk expressed strictly in terms of fundamental SI base units?

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Cevap: kgs2\text{kg} \cdot \text{s}^{-2}

Cevap

kgs2\text{kg} \cdot \text{s}^{-2}
The force constant kk is defined as force per unit extension (k=Fek = \frac{F}{e}). Since force has base units of kgms2\text{kg} \cdot \text{m} \cdot \text{s}^{-2} and extension has base units of m\text{m}, dividing force by extension yields kgms2m=kgs2\frac{\text{kg} \cdot \text{m} \cdot \text{s}^{-2}}{\text{m}} = \text{kg} \cdot \text{s}^{-2}.

Adım Adım Çözüm

1
Identify the defining formula and constituent quantities.
The force constant formula is k=Fek = \frac{F}{e}, where force FF is measured in newtons (N\text{N}) and extension ee is measured in metres (m\text{m}).
Determining SI base units requires substituting base dimensions into the governing physical equation.
2
Express force in fundamental SI base units using Newton's second law (F=maF = ma).
1 N=1 kgms21\text{ N} = 1\text{ kg} \cdot \text{m} \cdot \text{s}^{-2}.
Mass has fundamental unit kg\text{kg}, and acceleration has fundamental unit ms2\text{m} \cdot \text{s}^{-2}.
3
Substitute the base unit expression of force into the formula for kk and simplify.
\text{SI unit of } k = \frac{\text{kg} \cdot \text{m} \cdot \text{s}^{-2}}{\text{m}} = \text{kg} \cdot \text{s}^{-2}.
The unit of length (m\text{m}) in the numerator cancels out with the unit of length in the denominator.

Anahtar Kavram

Deriving SI units of physical quantities from fundamental base units using defining equations.
Fundamental and Derived Units Alıştırma Soruları — JAMB UTME | Examkin