Unit 1 - Practice Quiz

PHY110 50 Questions
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1 If is a scalar function, what does represent?

A. Divergence of
B. Laplacian of
C. Gradient of
D. Curl of

2 Which of the following represents the physical significance of the divergence of a vector field?

A. The direction of maximum increase
B. The net outflow of flux per unit volume
C. The rotational effect of the field
D. The circulation of the field around a loop

3 A vector field is said to be solenoidal if:

A.
B.
C.
D.

4 If a vector field is irrotational (conservative), which of the following is true?

A.
B.
C. The field cannot be expressed as a gradient
D.

5 What is the value of for any twice-differentiable vector field ?

A.
B. It depends on the coordinate system
C. 1
D. 0

6 Gauss's Divergence Theorem relates a surface integral to a:

A. Curl
B. Line integral
C. Volume integral
D. Gradient

7 Stokes' Theorem relates a line integral over a closed path to a:

A. Surface integral over a closed surface
B. Gradient of the field
C. Volume integral enclosed by the path
D. Surface integral over an open surface bounded by the path

8 Which mathematical equation represents Poisson's Equation in electrostatics?

A.
B.
C.
D.

9 Laplace's equation is a special case of Poisson's equation where:

A. The permittivity is infinite
B. The field is time-varying
C. The region is charge-free ()
D. The magnetic field is zero

10 The Equation of Continuity is a mathematical statement of the conservation of:

A. Mass
B. Momentum
C. Energy
D. Charge

11 The differential form of the continuity equation is given by:

A.
B.
C.
D.

12 For steady currents (DC), the continuity equation reduces to:

A.
B.
C.
D.

13 Which of Maxwell's equations is essentially Gauss's Law for Electrostatics?

A.
B.
C.
D.

14 The equation implies the non-existence of:

A. Displacement current
B. Electric dipoles
C. Magnetic monopoles
D. Static magnetic fields

15 Maxwell's third equation, , is the differential form of:

A. Gauss's Law
B. Lenz's Law only
C. Faraday's Law of Electromagnetic Induction
D. Ampere's Law

16 In Ampere's Circuital Law, the term added by Maxwell to correct the law for time-varying fields is called:

A. Displacement current
B. Conduction current
C. Eddy current
D. Convection current

17 The formula for displacement current density is:

A.
B.
C.
D.

18 Maxwell's modification of Ampere's Law is written as:

A.
B.
C.
D.

19 Displacement current arises due to:

A. Time-varying electric field
B. Flow of electrons in a wire
C. Flow of ions in a solution
D. Steady magnetic field

20 In free space (vacuum), the constitutive relation between and is:

A.
B.
C.
D.

21 The integral form of Maxwell's equation is:

A.
B.
C.
D.

22 The physical significance of in electrostatics is:

A. The electric field is non-conservative
B. Magnetic monopoles exist
C. The electric field is conservative
D. There is a time-varying magnetic field

23 Which of the following is the correct unit for Electric Flux Density ()?

A. Volts/meter ()
B. Coulombs/meter squared ()
C. Tesla ()
D. Coulombs ()

24 For a perfect dielectric, the conduction current density is:

A. Negative
B. Equal to displacement current
C. Infinite
D. Zero

25 The minus sign in Faraday's Law () represents:

A. Lenz's Law
B. Gauss's Law
C. Ampere's Law
D. Ohm's Law

26 Which vector identity is used to prove that magnetic monopoles do not exist () given that ?

A. Divergence of a Curl is zero
B. Curl of a Curl is Gradient of Divergence minus Laplacian
C. Divergence of a Gradient is the Laplacian
D. Curl of a Gradient is zero

27 Ampere's Circuital Law fails for time-varying fields because:

A. It violates conservation of energy
B. It only applies to vacuum
C. Magnetic fields cannot vary with time
D. It violates conservation of charge (Continuity Equation)

28 The ratio of conduction current density to displacement current density () is given by:

A.
B.
C.
D.

29 In the integral form of Maxwell's 4th equation, the term represents:

A. Conduction Current ()
B. Magnetic Flux
C. Electric Potential
D. Displacement Current ()

30 For a static magnetic field, which of the following is true?

A.
B.
C.
D.

31 Which theorem converts a volume integral of a scalar function's gradient into a surface integral?

A. Stokes' Theorem
B. Green's Theorem
C. Gradient Theorem (Generalized)
D. Gauss's Divergence Theorem

32 The operator is called the:

A. Hamiltonian
B. Div-Curl
C. Gradient
D. Laplacian

33 In Maxwell's equations, . Here represents:

A. Permittivity
B. Conductivity
C. Susceptibility
D. Permeability

34 If , what is ?

A.
B. 0
C. 3
D. 1

35 If , what is ?

A. 3
B.
C. 0
D.

36 The displacement current is equal to the conduction current in a parallel plate capacitor when:

A. The capacitor is being charged
B. Always (in terms of circuit continuity)
C. The capacitor is fully charged
D. The dielectric is perfect

37 Which of the following is NOT a vector field?

A. Current Density
B. Electric Field Intensity
C. Magnetic Flux Density
D. Electric Potential

38 Maxwell's equations predict that electromagnetic waves travel in free space with a speed of:

A.
B.
C.
D.

39 What is the physical interpretation of pointing in a specific direction?

A. It points in the direction of constant potential
B. It points in the direction of the greatest rate of increase of V
C. It points in the direction of the greatest rate of decrease of V
D. It is perpendicular to the electric field

40 The total current passing through a closed surface is zero implies:

A. Charge inside is conserved
B.
C. Kirchhoff's Current Law applies to the enclosed volume
D. The displacement current cancels the conduction current

41 Which quantity is conserved in the continuity equation?

A. Charge
B. Power
C. Flux
D. Voltage

42 In the derivation of the wave equation from Maxwell's equations for free space, the charge density and current density are set to:

A. Zero
B. Unity
C. Variable
D. Infinity

43 The curl of the gradient of electric potential is:

A. Zero
B. Electric Flux
C. Charge Density
D. Electric Field

44 Stokes' Theorem is applicable to:

A. Only scalar fields
B. Only time-varying fields
C. Only vector fields
D. Both scalar and vector fields

45 The region in which Laplace's equation is valid is called:

A. Sink region
B. Source region
C. Charge-free region
D. Conducting region

46 If the divergence of a vector field is positive at a point, that point acts as a:

A. Sink
B. Source
C. Vortex
D. Saddle point

47 The electric field is related to the potential by:

A.
B.
C.
D.

48 Which of the following equations represents the integral form of Ampere's Law without Maxwell's correction?

A.
B.
C.
D.

49 The concept of displacement current is associated with:

A. Magnetic field produced by a moving charge
B. Current in a resistor
C. Electric field produced by a static charge
D. Magnetic field produced by a changing electric field

50 For a vector field , the identity is physically significant because it leads to:

A. Conservation of charge
B. for steady currents
C. (Magnetic monopoles don't exist)
D. in electrostatics