Unit 1: Electromagnetic Theory - Practice Quiz

PHY110 — Engineering Physics 50 Questions
0 Correct 0 Wrong 50 Left
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1 If is a scalar function, what does represent?

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

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

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

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

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

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

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

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

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

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

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

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

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

A. Eddy current
B. Convection current
C. Conduction current
D. Displacement 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. Flow of electrons in a wire
B. Time-varying electric field
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. The electric field is conservative
C. Magnetic monopoles exist
D. There is a time-varying magnetic field

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

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

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

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

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

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

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

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

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

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

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

32 The operator is called the:

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

33 In Maxwell's equations, . Here represents:

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

34 If , what is ?

A. 0
B.
C. 1
D. 3

35 If , what is ?

A. 3
B.
C.
D. 0

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

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

37 Which of the following is NOT a vector field?

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

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

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

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

41 Which quantity is conserved in the continuity equation?

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

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. Unity
B. Zero
C. Infinity
D. Variable

43 The curl of the gradient of electric potential is:

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

44 Stokes' Theorem is applicable to:

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

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

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

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

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

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

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

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