Electromagnetic Field Theory MCQ Questions & Answers

Section 1 Section 2 Section 3 Section 4

81.
A force with which the plates of a parallel plate capacitor having charge Q and area of each plate A, attract each other is:
1. directly proportional to Q
2. directly proportional to Q²
3. inversely proportional to A
Of these statements which are correct?

A. 1 and 2 only

B. 2 and 3 only

C. 1 and 3 only

D. 1, 2 and 3

Answer & Solution Discuss in Board Save for Later

82.
A quarter-wave transformer matching a 75 Ω source with a 300 Ω load should have a characteristic impedance of

A. 50 Ω

B. 100 Ω

C. 150 Ω

D. 200 Ω

Answer & Solution Discuss in Board Save for Later

83.
The phase velocity of a plane wave given by E_x = E₀ cos(ωt - βz) with a frequency of 5.0 GHz and a wavelength in the material medium of 3.0 cm is:

A. 3.0 × 10⁸ m/sec

B. 1.5 × 10⁸ m/sec

C. 5 × 10⁸ m/sec

D. None

Answer & Solution Discuss in Board Save for Later

84.
A plane wave of wavelength λ is travelling in a direction making an angle 30° with positive x-axis and 90° with positive y-axis. The $$\overrightarrow E $$ field of the plane wave can be represented as (E₀ is a constant)

A. $$\overrightarrow E = \hat y{E_0}{e^{j\left( {\omega t - \frac{{\sqrt 3 \pi }}{\lambda }x - \frac{\pi }{\lambda }z} \right)}}$$

B. $$\overrightarrow E = \hat y{E_0}{e^{j\left( {\omega t - \frac{\pi }{\lambda }x - \frac{{\sqrt 3 \pi }}{\lambda }z} \right)}}$$

C. $$\overrightarrow E = \hat y{E_0}{e^{j\left( {\omega t + \frac{{\sqrt 3 \pi }}{\lambda }x + \frac{\pi }{\lambda }z} \right)}}$$

D. $$\overrightarrow E = \hat y{E_0}{e^{j\left( {\omega t - \frac{\pi }{\lambda }x + \frac{{\sqrt 3 \pi }}{\lambda }z} \right)}}$$

Answer & Solution Discuss in Board Save for Later

85.
A boundary separates two magnetic materials of permeability µ₁ and µ₂. The magnetic field vector in µ₁ is H₁ with a normal component H_n₁ and tangential component H_t₁ while that in µ₂ is H₂ with normal component H_n₂ and a tangential component H_t₂. Then the derived conditions would be

A. H₁ = H₂ and H_t₁ = H_t₂

B. H_t₁ = H_t₂ and µ₁H_n₁ = µ₂H_n₂

C. H₁ = H₂ and µ₁H_n₁ = µ₂H_n₂

D. H₁ = H₂, H_t₁ = H_t₂ and µ₁H_n₁ = µ₂H_n₂

Answer & Solution Discuss in Board Save for Later

86.
Consider an impedance Z = R + jX marked with point P in an impedance Smith chart as shown in figure. The movement from point P along a constant resistance circle in the clockwise direction by an angle 45° is equivalent to-

A. adding an inductance in series with Z

B. adding a capacitance in series with Z

C. adding an inductance in shunt across Z

D. adding a capacitance in shunt across Z

Answer & Solution Discuss in Board Save for Later

87.
An electromagnetic wave having frequency f₀ gets attenuated by a factor of e^-2 after propagating a distance d in a good conductor. If the signal frequency is now reduced to 0.5 f₀, after travelling the same distance d in the same conductor, the signal will get attenuated by a factor of:

A. e^-4

B. e^-2√2

C. e^-√2

D. e^-1

Answer & Solution Discuss in Board Save for Later

88.
The wave which 'lie down and dies' is called

A. Space wave

B. Ground wave

C. Sky wave

D. Spherical wave

Answer & Solution Discuss in Board Save for Later

89.
If a lossless line is terminated with a load impedance 40 + j30 Ω, then the characteristic impedance of the line for minimum possible standing wave ratio (SWR) will be

A. 70 Ω

B. 25 Ω

C. 50 Ω

D. 100 Ω

Answer & Solution Discuss in Board Save for Later

90.
Two thin parallel wires are carrying current along the same direction. The force experienced by one due to the other is:

A. Parallel to the lines

B. Perpendicular to the lines and attractive

C. Perpendicular to the lines and repulsive

D. Zero

Answer & Solution Discuss in Board Save for Later

1 2 3 4 5 6 7 8 9 10

Electromagnetic Field Theory MCQ Questions & Answers | ECE

81. A force with which the plates of a parallel plate capacitor having charge Q and area of each plate A, attract each other is: 1. directly proportional to Q 2. directly proportional to Q2 3. inversely proportional to A Of these statements which are correct?

Answer & Solution

82. A quarter-wave transformer matching a 75 Ω source with a 300 Ω load should have a characteristic impedance of

Answer & Solution

83. The phase velocity of a plane wave given by Ex = E0 cos(ωt - βz) with a frequency of 5.0 GHz and a wavelength in the material medium of 3.0 cm is:

Answer & Solution

84. A plane wave of wavelength λ is travelling in a direction making an angle 30° with positive x-axis and 90° with positive y-axis. The $$\overrightarrow E $$ field of the plane wave can be represented as (E0 is a constant)

Answer & Solution

85. A boundary separates two magnetic materials of permeability µ1 and µ2. The magnetic field vector in µ1 is H1 with a normal component Hn1 and tangential component Ht1 while that in µ2 is H2 with normal component Hn2 and a tangential component Ht2. Then the derived conditions would be

Answer & Solution

86. Consider an impedance Z = R + jX marked with point P in an impedance Smith chart as shown in figure. The movement from point P along a constant resistance circle in the clockwise direction by an angle 45° is equivalent to-

Answer & Solution

87. An electromagnetic wave having frequency f0 gets attenuated by a factor of e-2 after propagating a distance d in a good conductor. If the signal frequency is now reduced to 0.5 f0, after travelling the same distance d in the same conductor, the signal will get attenuated by a factor of:

Answer & Solution

88. The wave which 'lie down and dies' is called

Answer & Solution

89. If a lossless line is terminated with a load impedance 40 + j30 Ω, then the characteristic impedance of the line for minimum possible standing wave ratio (SWR) will be

Answer & Solution

90. Two thin parallel wires are carrying current along the same direction. The force experienced by one due to the other is:

Answer & Solution

Read More Section(Electromagnetic Field Theory)

81.
A force with which the plates of a parallel plate capacitor having charge Q and area of each plate A, attract each other is:
1. directly proportional to Q
2. directly proportional to Q²
3. inversely proportional to A
Of these statements which are correct?

82.
A quarter-wave transformer matching a 75 Ω source with a 300 Ω load should have a characteristic impedance of

83.
The phase velocity of a plane wave given by E_x = E₀ cos(ωt - βz) with a frequency of 5.0 GHz and a wavelength in the material medium of 3.0 cm is:

84.
A plane wave of wavelength λ is travelling in a direction making an angle 30° with positive x-axis and 90° with positive y-axis. The $$\overrightarrow E $$ field of the plane wave can be represented as (E₀ is a constant)

86.
Consider an impedance Z = R + jX marked with point P in an impedance Smith chart as shown in figure. The movement from point P along a constant resistance circle in the clockwise direction by an angle 45° is equivalent to-

87.
An electromagnetic wave having frequency f₀ gets attenuated by a factor of e^-2 after propagating a distance d in a good conductor. If the signal frequency is now reduced to 0.5 f₀, after travelling the same distance d in the same conductor, the signal will get attenuated by a factor of:

88.
The wave which 'lie down and dies' is called

89.
If a lossless line is terminated with a load impedance 40 + j30 Ω, then the characteristic impedance of the line for minimum possible standing wave ratio (SWR) will be

90.
Two thin parallel wires are carrying current along the same direction. The force experienced by one due to the other is: