Understanding Physical Quantities in Physics
48 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What are the dimensions of velocity in terms of mass, length, and time?

  • [M0L0T-1]
  • [M0L1T0]
  • [M0L1T-1] (correct)
  • [M1L0T-1]

How is acceleration formulated dimensionally?

  • [M0L2T-2]
  • [M1L0T-2]
  • [M0L1T-2] (correct)
  • [M1L1T-2]

What dimensional formula corresponds to pressure?

  • [M1L0T-2]
  • [M1L1T-2]
  • [M0L1T-2]
  • [M1L-1T-2] (correct)

Which of the following relates to the dimensions of work or energy?

<p>[M1L2T-2] (D)</p> Signup and view all the answers

What is the dimensional formula for momentum?

<p>[M1L1T-1] (B)</p> Signup and view all the answers

What are the dimensions of a in the equation related to volume V?

<p>M1L5T-2 (B)</p> Signup and view all the answers

Which of the following statements about dimensionless quantities is true?

<p>All trigonometric functions are dimensionless. (D)</p> Signup and view all the answers

What is the correct derivation of dimensions for pressure P in terms of M, L, and T?

<p>M1L-1T-2 (C)</p> Signup and view all the answers

Which of the following quantities is dimensionless?

<p>sin(θ) (B)</p> Signup and view all the answers

If V = L^3, what are the dimensions for V^2?

<p>M0L6T0 (C)</p> Signup and view all the answers

What are the derived units of time t in terms of dimensions?

<p>M0L0T1 (D)</p> Signup and view all the answers

In the expression F = sin(βt), what can we conclude about the dimensions of F?

<p>F has dimensions of force. (D)</p> Signup and view all the answers

If the term loge(x) is used, what can be inferred about x?

<p>x is a dimensionless quantity. (D)</p> Signup and view all the answers

What is the correct expression for mass in terms of velocity (V), force (F), and time (T)?

<p>M = (Some Number) V^-1 F^1 T^1 (A)</p> Signup and view all the answers

Which of the following is the unit of force in the MKS system?

<p>kg m/s^2 (A)</p> Signup and view all the answers

What dimension is used for energy according to the solution provided?

<p>[M^0L^2T^-2] (B)</p> Signup and view all the answers

To express energy E in terms of V, F, and T, which equation correctly represents the relationship?

<p>[E] = [V^1][F^1][T^1] (A)</p> Signup and view all the answers

If the mass is expressed in terms of fundamental quantities, what would be the value of c when deriving the energy relationship?

<p>1 (B)</p> Signup and view all the answers

Which of the following statements about dimensional analysis is correct?

<p>Dimensions can be expressed in combinations of basic quantities. (B)</p> Signup and view all the answers

When calculating the dimensions from $[E] = [M^a][L^b][T^c]$, what does 'a' represent when comparing energy and mass dimensions?

<p>1 (A)</p> Signup and view all the answers

What is the dimension of force noted in the text?

<p>[M^1L^1T^-2] (A)</p> Signup and view all the answers

Which expression correctly represents the relationship for T derived from dimensional analysis?

<p>T = (Some Number) (m)^0 (λ)^(1/2) (g)^(-1/2) (B)</p> Signup and view all the answers

What is the value of 'c' when solving for the dimensions of T?

<p>-1/2 (D)</p> Signup and view all the answers

What is the derived expression for the natural frequency (f) of a closed pipe based on dimensional analysis?

<p>f = (Some Number) (λ)^(1/2) (ρ)^(1/2) (P)^0 (A)</p> Signup and view all the answers

How do you experimentally determine the quantity referred to as 'Some Number' in the context?

<p>By measuring the length of the pendulum and its time period. (C)</p> Signup and view all the answers

From the dimensional analysis, what does the dimension M^(0)L^(0)T^(1) correspond to?

<p>A time period (B)</p> Signup and view all the answers

Which of the following equations correctly balances the powers for mass (M) in the natural frequency equation?

<p>0 = b + c (A)</p> Signup and view all the answers

What is the relationship between 'b' and 'c' derived from the dimensions of the natural frequency equation?

<p>b + c = 0 (D)</p> Signup and view all the answers

When solving for the time period T, which of the following statements is true about the quantity represented by 'g'?

<p>It is a constant that represents gravitational acceleration. (D)</p> Signup and view all the answers

What is the derived value for 'Some Number' when $ heta = 1m$ and T = 2 sec?

<p>6.28 (C)</p> Signup and view all the answers

What is the dimensional formula for electric field E?

<p>M1L1T–3A–1 (B)</p> Signup and view all the answers

Which of the following represents the correct dimensional formula for resistance R?

<p>M1L2T–3A–2 (A)</p> Signup and view all the answers

What is the dimensional formula for permittivity in vacuum (ε0)?

<p>M–1L–3T4A2 (A)</p> Signup and view all the answers

How is the capacitance C defined dimensionally?

<p>M–1L–2T4A2 (C)</p> Signup and view all the answers

What is the dimensional formula for magnetic permeability in vacuum (μ0)?

<p>M1L1T–2A–2 (D)</p> Signup and view all the answers

What does the Stefan's constant (σ) dimensionally represent?

<p>M1L2T–2K–4 (C)</p> Signup and view all the answers

The inductance L has which of the following dimensional formulas?

<p>M1L2T–2A–2 (C)</p> Signup and view all the answers

How is the thermal conductivity K dimensionally expressed?

<p>M1L2T–2K–1 (A)</p> Signup and view all the answers

What is the dimensional formula for electrical potential V?

<p>M1L2T–3A–1 (B)</p> Signup and view all the answers

What is the dimensional formula for magnetic field B?

<p>M1L1T–2A–1 (B)</p> Signup and view all the answers

What is the equivalent of 6.67 × 10–11 kg s²/m³ in the CGS system?

<p>6.67 × 10–8 gs²/cm³ (C)</p> Signup and view all the answers

To convert a speed of 90 km/hour to m/s, which factor is used?

<p>Multiply by 18 (A)</p> Signup and view all the answers

Which of the following correctly converts a density of 2 g/cm³ into kg/m³?

<p>2 × 10³ kg/m³ (B)</p> Signup and view all the answers

What is the value of 7 pm when converted into μm?

<p>7 × 10⁻⁶ μm (D)</p> Signup and view all the answers

In dimensional analysis, which of the following units is called a dyne?

<p>g·cm/s² (A)</p> Signup and view all the answers

What is the correct conversion factor to change 5 m/s to km/hour?

<p>Multiply by 3.6 (D)</p> Signup and view all the answers

Which equation correctly expresses the conversion of acceleration from m/s² to cm/s²?

<p>a = a × 10² (B)</p> Signup and view all the answers

What is the output velocity when converting 90 km/hour into m/s?

<p>25 m/s (B)</p> Signup and view all the answers

Flashcards

Density

Mass per unit volume

Velocity

Rate of change of displacement

Acceleration

Rate of change of velocity

Force

Mass times acceleration

Signup and view all the flashcards

Work/Energy

Force times displacement

Signup and view all the flashcards

Dimensions of V^2

The dimensions of volume squared are L^6

Signup and view all the flashcards

Dimensions of [a]

The dimensions of [a] are M L^5 T^-2

Signup and view all the flashcards

Dimension of Pressure

The dimension of pressure is ML^-1 T^-2

Signup and view all the flashcards

Dimensionless trigonometric functions

sin(theta), cos(theta), tan(theta) are dimensionless functions.

Signup and view all the flashcards

Dimensionless exponential functions

e, loge are dimensionless functions.

Signup and view all the flashcards

Dimensionless argument in trigonometric function

The argument within trigonometric functions (sin, cos, tan) must be dimensionless.

Signup and view all the flashcards

Dimension of Volume

[V]=L^3

Signup and view all the flashcards

Dimension of Time

[t]=T

Signup and view all the flashcards

Dimensional Analysis

A method used to determine the units of a physical quantity by expressing it as a combination of fundamental units (like meters, kilograms, and seconds).

Signup and view all the flashcards

Time Period (T)

The time taken for one complete oscillation or cycle of a periodic motion, like a pendulum swinging.

Signup and view all the flashcards

Dimensional Formula

An expression representing the units of a physical quantity using fundamental dimensions (mass, length, time) raised to specific powers.

Signup and view all the flashcards

Equating Dimensions

Matching the powers of each dimension (mass, length, time) on both sides of an equation to ensure dimensional consistency.

Signup and view all the flashcards

Coefficient (Some Number)

A numerical factor obtained through experimental measurement that scales the dimensional formula to give the actual value of the quantity.

Signup and view all the flashcards

Natural Frequency (f)

The frequency at which a system vibrates freely without external forces.

Signup and view all the flashcards

Closed Pipe

A pipe with one end sealed and the other open, producing sound waves with specific resonance characteristics.

Signup and view all the flashcards

Frequency (f)

The number of oscillations or cycles per unit time, measured in Hertz (Hz).

Signup and view all the flashcards

Fundamental Quantities

Basic quantities that cannot be broken down into simpler quantities. Examples include mass, length, and time.

Signup and view all the flashcards

Derived Quantity

A quantity that can be expressed in terms of fundamental quantities.

Signup and view all the flashcards

Dimension of a Quantity

The expression of a physical quantity in terms of fundamental quantities. Represented by square brackets, e.g., [mass] = [M].

Signup and view all the flashcards

Unit of a Physical Quantity

A standard value used for measuring a physical quantity. Examples include meter (m) for length, kilogram (kg) for mass.

Signup and view all the flashcards

How to Find the Unit of Force

  1. Determine the dimension of force ([Force] = [M1L1T–2]), then substitute the units of the fundamental quantities.
Signup and view all the flashcards

Expressing Mass in terms of Velocity, Force, and Time

Use dimensional analysis to find the relationship between mass and the given fundamental quantities.

Signup and view all the flashcards

Expressing Energy in terms of Velocity, Force, and Time

Similar to expressing mass, use dimensional analysis to find the relationship between energy and the given fundamental quantities.

Signup and view all the flashcards

MKS System

A system of units using meters (m), kilograms (kg), and seconds (s).

Signup and view all the flashcards

Dyne

The unit of force in the CGS system. It is equal to 1 g cm/s².

Signup and view all the flashcards

Convert km/h to m/s

To convert kilometers per hour (km/h) to meters per second (m/s), multiply by 5/18.

Signup and view all the flashcards

Convert pm to m

To convert picometers (pm) to micrometers (m), divide by 10⁶.

Signup and view all the flashcards

SI Units

Units of measurement used in the International System of Units (SI). Examples include meter (m), kilogram (kg), and second (s).

Signup and view all the flashcards

What is the dimension of Charge (q)?

The dimension of charge (q) is [A1T1], which represents Ampere-second.

Signup and view all the flashcards

What is the dimension of Permittivity in Vacuum (ε0)?

The dimension of permittivity in vacuum (ε0) is [M-1L-3T4A2], which represents a combination of mass, length, time, and current.

Signup and view all the flashcards

What is the dimension of Electric Field (E)?

The dimension of electric field (E) is [M1L1T-3A-1], which represents a force per unit charge.

Signup and view all the flashcards

What is the dimension of Electrical Potential (V)?

The dimension of electrical potential (V) is [M1L2T-3A-1], which represents potential energy per unit charge.

Signup and view all the flashcards

What is the dimension of Resistance (R)?

The dimension of resistance (R) is [M1L2T-3A-2], which represents the opposition to current flow.

Signup and view all the flashcards

What is the dimension of Capacitance (C)?

The dimension of capacitance (C) is [M-1L-2T4A2], which represents the ability to store electrical charge.

Signup and view all the flashcards

What is the dimension of Magnetic Field (B)?

The dimension of magnetic field (B) is [M1LOT-2A-1], which represents the strength of the magnetic field.

Signup and view all the flashcards

What is the dimension of Inductance (L)?

The dimension of inductance (L) is [M1L2T-2A-2] which represents a measure of how much a circuit opposes a change in current.

Signup and view all the flashcards

What is the dimension of Thermal Conductivity (k)?

The dimension of thermal conductivity (k) is [M1L1T-3K-1] which represents the ability of a material to transfer heat.

Signup and view all the flashcards

Study Notes

Physical Quantities

  • Physical quantities are measurable quantities used to describe the laws of physics.
  • Examples include length, velocity, acceleration, force, time, pressure, mass, and density.
  • Physical quantities are categorized into three types: fundamental, derived, and supplementary.

Fundamental Quantities

  • These are basic quantities from which other quantities are derived.
  • Seven fundamental quantities are defined in the International System of Units (SI): length, mass, time, temperature, electric current, luminous intensity, and amount of substance.
  • These quantities are independent of each other.
  • Length (L), Mass (M), Time (T), Temperature (K), Electric Current (A), Luminous Intensity (Cd), Amount of Substance (mol).

Derived Quantities

  • Derived quantities are expressed in terms of fundamental quantities.
  • Examples include velocity, acceleration, force, momentum, work, energy, power, etc.
  • Derived quantities are related to fundamental quantities through equations.

Supplementary Quantities

  • Supplementary quantities are independent physical quantities needed to define other quantities such as plane angle and solid angle.

Dimensions of Physical Quantities

  • Dimensions represent the power to which fundamental quantities are raised to express a physical quantity.
  • The dimensions of a physical quantity are enclosed in square brackets [ ].
  • Example: [Length] = [L], [Mass] = [M], [Time] = [T]

Dimensional Formula

  • The representation of a physical quantity in terms of fundamental quantities with their respective powers is known as a dimensional formula.

Dimensional Analysis

  • Dimensional analysis is used to check the dimensional correctness of a physical equation.
  • The dimensions of the left-hand side (LHS) and the right-hand side (RHS) of an equation must be the same.

Dimensions of Physical Constants

  • Physical constants also have dimensions.
  • The dimensions of a physical constant can be determined from the equation in which it appears.

Some Special Features of Dimensions

  • Quantities can be added or subtracted only if they have the same dimensions.
  • Numbers are dimensionless.
  • Trigonometric, logarithmic, and exponential functions are dimensionless.

Uses of Dimensions

  • To check the correctness of a formula.
  • To derive new formulas.

SI Units

  • SI units are internationally accepted standard units for measuring physical quantities.

  •  Examples include meters for length, kilograms for mass, seconds for time, etc...

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Description

This quiz covers the essential concepts of physical quantities in physics, including fundamental and derived quantities. You will explore how these quantities are measured and categorized, and their significance in the laws of physics. Test your knowledge on the International System of Units (SI) and their applications.

More Like This

الكميات الفيزيائية
15 questions
Physical Quantities in Physics
34 questions
Physical Quantities and Their Units
45 questions
Use Quizgecko on...
Browser
Browser