Electromagnetic Field Theory

A square corner reflector is used in

In microwave communication links, when fading due to rain attenuation occurs then technique adopted for solving the problem would include

The power gain of a half-wave dipole with respect to an isotropic radiator is

MUF is highest in periods of greatest sunspot activity.

The attenuation in waveguide above to cut off frequency

A waveguide operated below cut off frequency can be used as

The wave in wave guide has

Radiation intensity in a given direction is the

Which of the following impedance inversion is obtained?

When a conductor moves in the field, so that it makes an angle 8 with the lines of flux, the force F is given as : F = Bl sin2 0.

Which one of the following statements does not pertain to the equation? $$
abla .overrightarrow { ext{B}} = 0?$$

The magnitude of reflection coefficient is:

A 75 ohm transmission line is to be terminated in two resistive loads R 1 and R 2 such that the standing patterns in the two cases have the same SWR. To obtain the desired result, the values of R 1 and R 2 (in ohms) should be

Two lossy lines are to be joined end to end. The first line is 10 m long and has a loss rating of 0.20 dB/m. The second lines is 15 m long and has a loss rating of 0.10 dB/m. The reflection coefficient at the junction (line 1 to line 2) is Γ = 0.30. The input power (to line 1) is 100 mW. Determine the total loss of the combination in dB to the output end of line 2.

The potential (scalar) distribution is given as V = 10y 4 + 20x 3 . If ε 0 is the permittivity of free space, what is the charge density ρ at the point (2, 0)?

A plane wave propagating in the dielectric medium has an electric field given as E x = E 0 Cos(2.6 × 10 10 t - 100z). The phase velocity of plane wave is:

Given potential V = 2x 2 y + z 2 , then the electric field at (1, 1, 0) is

Maxwell's major contribution to EM theory was to assert

Consider the following statement about a transmission line having non-zero Parameters R, L, G and C: 1. By proper choice of the parameters, the line can be made lossless even though R and G are non-zero 2. The line will have both amplitude and phase distortion in general Of the statements

With wavelength λ in increasing order, which one of the following combination is correct?

The voltage reflection coefficient at the load end of a transmission line is

In air the lossless transmission line of length 50 cm with L = 10 μH/m, C = 40 pF/m is operated at 25 MHz. Its electrical path length is

For a wave travelling in negative Z direction the value of $$frac{{{ ext{Ey}}}}{{{ ext{Hx}}}}$$ xa0is:

A coaxial-cable with an inner diameter of 1 mm and outer diameter of 2.4 mm is filled with a dielectric of relative permittivity 10.89. Given $${mu _0} = 4pi imes {10^{ - 7}}{ ext{H/m}},,{varepsilon _0} = frac{{{{10}^{ - 9}}}}{{36pi }}{ ext{F/m}}{ ext{.}}$$ The characteristic impedance of the cable is

The frequency of a sound wave is 25 Hz and its wavelength is 4 m. What is the distance travelled by the sound wave in 2?

From a solution of wave equation in a conducting medium we can determine various parameters. In the light of this, match List-I with List-II and select the correct answer using the options given below the lists: List-I (Parameter) List-II (Expression) a. Propagation constant 1. $${left( {frac{2}{{omega mu sigma }}}
ight)^{frac{1}{2}}}$$ b. Skin depth 2. $${left( {frac{{omega {mu _0}}}{{2sigma }}}
ight)^{frac{1}{2}}}$$ c. Sheet resistance 3. $${left( {jomega {mu _0}sigma }
ight)^{frac{1}{2}}}$$ 4. $${left( {frac{{omega {mu _0}sigma }}{2}}
ight)^{ - frac{1}{2}}}$$

The mode used in the laboratory bench is

Consider a rectangular coordinate system (x, y, z) with unit vectors a x , a y and a z . A plane wave travelling in the region z ≥ 0 with electric field vector E = 10cos(2 × 10 8 t + βz)a y is incident normally on the plane at z = 0, where β is the phase constant. The region z ≥ 0 is in the free space and the region z < 0 is filled with a lossless medium (permittivity ε = ε 0 , permeability µ = 4µ 0 , where ε 0 = 8.85 × 10 12 F/m and µ 0 = 4π × 10 -7 H/m). The value of the reflection coefficient is

If a right hand circularly polarised wave is incident on a perfect conductor. The reflected wave is:

The maximum usable frequency of an ionospheric layer at 60° incidence at with 8 MHz critical frequency is

To couple a co-axial line to a parallel line wire it is best to use

Consider the following statements regarding an electrostatic field: 1. It is irrotational 2. It is solenoidal 3. It is static only from a macroscopic view point 4. Work done in moving a charge in the field from one point to another is independent of the path of movement Which of these statements are correct?

If the electric field established by three point charges Q, 2Q and 3Q exert a force 3F on 3Q and 2F on 2Q, then what is the force exerted on the point charge Q?

A transmission line has primary constants R, L, G and C and secondary constants Z 0 and γ = (α + jβ). If the line is lossless, then

An infinitely long uniform solid wire of radius a carries uniform dc current of density $$overrightarrow { ext{J}} .$$ The magnetic field at a distance r from the center of the wire is proportional to

A parallel plate air-filled capacitor has plate area of 10 -4 m 2 and plate separation of 10 -3 m. It is connected to a 2 V, 1.8 GHz source. The magnitude of the displacement current is $$left( {{varepsilon _0} = frac{1}{{36pi }} imes {{10}^{ - 9}}{ ext{F}}{{ ext{m}}^{ - 1}}}
ight)$$

If the electric field vector is $$overline E = - 2{overline a _x} + 3{overline a _y} + 5{overline a _z}$$ xa0 xa0 and the magnetic field vector is $$overline H = {overline a _x} + 3{overline a _y} - 4{overline a _z},$$ xa0 xa0 then $$overline E imes overline H $$ xa0is equal to

Which of the following equations results from the circuital form of Ampere's law?

If the reflection coefficient is $$frac{1}{5}$$, what is the corresponding VSWR?

The input impedance of a short circuited line of length less than quarter wave length is purely

Maxwell's equation for EM waves can be applied to 1. Dielectric medium 2. Conductive medium 3. Plasma 4. Free space Select the correct choice:

What does the expression $$frac{1}{2}overrightarrow J .overrightarrow A $$ xa0represent?

If the potential difference between points A (1, 0, 0) and B (2, 0, 0) is 10 V, determine d for point C (d, 0, 0), when V BC is 6 V in a uniform field.

Following equations represent four travelling waves. Which one has the maximum speed?

A and B are two points at same distance from the centre of a short electric dipole on axial line and equatorial line respectively. E 1 and E 2 are respectively the resultant electric fields due to the dipole at these points. Identify the only correct condition between E 1 and E 2 from the following for this situation.

What is not correct about a transmission line terminated in its characteristic impedance?

Find the work done when a force $$F = left( {vec i + 2vec j + 3vec k}
ight)N$$ xa0 xa0 acting on a particle takes it from the point $${{vec r}_1} = left( {vec i + vec j + vec k}
ight)m$$ xa0 xa0 to the point $${{vec r}_2} = left( {vec i - vec j + 2vec k}
ight)m$$

A transmission line is distortionless if

The intrinsic impedance η of a conducting medium for which σ = 58 Ms/m, µ r = 1 at a frequency of 100 MHz is

A charge Q 2 = 8.854 × 10 -9 C is located in a vacuum at P 2 (2, 3, 1). The force on Q 2 due to a charge Q 1 = 4π × 10 -3 C at P 1 (2, 2, 1) is: (Note : All the coordinates are measured in Meters. a x , a y and a z are unit vectors in X, Y and Z direction respectively.)

The displacement current can be represented as

What is the value of the magnetic vector potential due to an infinitesimally small current element, evaluated at infinite distance from it?

A steel pipe is constructed of a material for which µ r = 200 and σ = 5 × 10 6 mho/m. The outer and inner radii are 8 and 6 mm respectively and the length is 80 m. If the total current carried by the pipe is 2cos10 4 πt A,Then the skin depth will be

If the short circuit and open circuit impedance of a line are 5 Ω and 20 Ω respectively the characteristic impedance is given by

The characteristic impedance of a co-axial cable depends on diameter of

In general attenuation per unit length in a coaxial cable:

What would be the standing wave ratio (SWR) for a line with reflection coefficient equal to 0.49?

When a plane electromagnetic wave is incident normally on the boundary between two lossless dielectric media, the transmission coefficient for magnetic field intensity $$overrightarrow H $$ is

The potential at the centroid of an equilateral triangle of side $$rsqrt 3 $$ xa0due to three equal positive point charges each of value q and placed at the vertices of the triangle would be:

Consider the following statements: For a 10 m long common power line connecting a switch to a light bulb 1. It is distributed circuit 2. Time delay for propagation through it is negligible 3. It is in the form of a shielded coaxial cable of circular cross-section 4. As the intensity of the lamp varies, input impedance of this line also changes Which of the above statements is/are correct?

The wavelength of the wave having propagation constant (0.314 + j0.628) per metre is equal to:

Many circles are drawn in a Smith chart used for transmission line calculations. The circles shown in the figure represent

Find the SWR, if the reflection coefficient is 0.8.

A dual directional coupler is connected in a microwave reflectometer measurement setup. The reading of the power meter in the forward direction is 100 mw and in the reverse direction 4 mw. The VSWR is

The characteristics impedance of quarter wave transformer with load and input impedances given by 30 and 75 respectively is-

If $$overrightarrow E = left( {{{hat a}_x} + j{{hat a}_y}}
ight){e^{ikz - jomega t}}$$ xa0 xa0and $$overrightarrow H = left( {frac{k}{{omega mu }}}
ight)left( {{{hat a}_y} + j{{hat a}_x}}
ight){e^{ikz - jomega t}},$$ xa0 xa0 xa0 the time averaged poynting vector is

For distortion less transmission through a channel, the channel should be such that

An electromagnetic wave propagates through a lossless insulator with a velocity 1.5 × 10 10 cm/s. Calculate the electric and magnetic properties of the insulator if its intrinsic impedance is 90 π ohms.

For a lossless transmission line L = 0.35 µH/m. C = 90 pF/m and frequency = 500 MHz. Then the magnitude of propagation constant is:

The gradient of the function f(x, y) = x + y at the point (0, 0) is

The critical frequency of ‘F’ layer is greater than 30 MHz.

Which of the following statement regarding waveguides is incorrect?

A rectangular waveguide is a

Tropospheric scatter is used with frequencies in the

A Yagi antenna has a driven antenna

In case of antenna the ratio of the power radiated in the desired direction to the power radiated in the opposite direction is known as

The frequency range for satellite communication is

The static electric field in a conductor is

The skip distance is the maximum distance upto which ionospheric reflection is possible.

Parabolic and lens antenna used at

Which one of the following statements is correct?

When compared with stripline, the major disadvantage of microstrip line is

Some unknown material has a conductivity 10 6 mho/m and a permeability of 4π × 10 -7 H/m. The skin depth for the material at 1 GHz is

Match List-I with List-II and select the correct answer using the options given below: List-I (Load impedance) List-II (Value of Reflection Coefficient) a. Short circuit 1. 0 b. Open Circuit 2. -1 c. Line characteristic impedance 3. +1 d. 2 × line characteristic impedance 4. $$ + frac{1}{3}$$

The conducting thin coils X and Y (identical except for a thin cut in coil Y) are placed in a uniform magnetic field which is decreasing at a constant rate. If the plane of the coils is perpendicular to the field lines, which of the following statement is correct? As a result, emf is induced in:

Who developed the concept of time varying electric field producing a magnetic field?

Electromagnetic waves are produced by

The characteristic impedance of a cable is about

The VSWR of a microwave unit is 1.5, the return loss is:

A medium is divided into regions I and II about x = 0 plane, as shown in the figure below. An electromagnetic wave with electric field $${overrightarrow E _1} = 4{{hat a}_x} + 3{{hat a}_y} + 5{{hat a}_z}$$ xa0 xa0 is incident normally on the interface from region-I. The electric field $${overrightarrow E _2}$$xa0in region-II at the interface is

Which of the following mechanisms is NOT for removing particulate matter from gas streams.

Polarization is characteristic of EM wave that gives the direction of

For a transmission of wave from a dielectric medium of permittivity ε 1 into a dielectric medium of lower permittivity ε 2 and (ε 1 > ε 2 ) the critical angle of incidence θ c (relative to the interface) is given by

A parallel plate capacitor of 100 pF having an air dielectric is charged to 10 kV. It is then electrically isolated. The plates are pulled away from each other until the distance is ten times more than before. Estimate the energy needed to pull the plates.

The intrinsic impedance of free space is 377 Ω. The approximate intrinsic impedance of a medium with relative permittivity and permeability of 4 and 1 respectively will be

In a uniform plane wave 'E' and 'H' are related by

In a coaxial transmission line (ε r = 1), the electric field intensity is given by: $$E = frac{{100}}{
ho }cos left( {{{10}^9}t - 6z}
ight){u_p}{ ext{V/m}}$$ The displacement current density is

The torque (in N - m) acting on a circular current loop of radius 1 mm in the xy-plane, connected at the origin and with current 0.1 A flowing in the sense of increasing φ in a magnetic field $$B = {10^{ - 5}}left( {2{{hat a}_x} - 2{{hat a}_y} + {{hat a}_z}}
ight){ ext{Wb/}}{{ ext{m}}^2}{ ext{ is:}}$$

When a line short circuited at far end, the minimum voltage occurs at

A 3 µF capacitor is charged by a constant current of 2 µA for 6 seconds. The voltage across the capacitor to the end of charging will be:

The maxwell's equation which interprets that isolated magnetic poles do not exist is

When the electric field is maximum value, the magnetic energy of a cavity is

When waves travel along a transmission line from a generator to load, through which region is power transmission taking place?

The electric field lines and equipotential lines

A shape of homogeneous linear dielectric material of dielectric constant ≥ 1 is placed in a uniform electric field E 0 , then the electric field E that exists inside the sphere is:

The total flux at the end of a long bar magnet is 500 µWb. The end of the bar magnet is withdrawn through a 1000-turn coil in $$frac{1}{{10}}$$ second. The e.m.f. generated across the terminals of the coil is:

The wave propagation in plasma is known as

What will be the equipotential surfaces for a pair of equal and opposite line charges?

The fundamental postulate of magnetostatic $$
abla overline { ext{B}} = 0$$ xa0in free space is based on

Slotted line with tunable probe is not used to measure

MUF is depend upon

The radiation pattern of loop antenna is

When a current carrying conductor is brought into magnetic field, the force that moves the conductor depends upon

If a and b are the dimensions of waveguide then

When a wave is incident from the more dense into a less dense medium at an angle equal to or exceeding the critical angle, the wave suffers total internal __________ .

Due to which of the following reasons a lightning conductor on top of a building is made into a pointed spike?

The useful magnetic flux obtainable from any closed surface is

When the phase velocity of an EM wave depends on frequency in any medium the phenomenon is called

A satellite that simply reflect back the signals from one region of the earth to the other region is known as

The main disadvantage of the two-hole directional coupler is

For loss less transmission line L = 0.35 µH/m, C = 90 pF/m and frequency = 500 MHz. Then the magnitude of the propagation constant is

The intrinsic impedance of free space is

The magnitude of Coulomb's force of repulsion between two alpha particles (helium ions) in space 10 mm apart is:

If a transmission line terminated with a load equal to be characteristic impedance the reflection co-efficient is

The group delay function τ(ω) is related to phase function φ(ω) as

Blue colour of sky look due to

A vector [overrightarrow P ] is given by [overrightarrow P = {x^3}y{overrightarrow a _x} - {x^2}{y^2}{overrightarrow a _y} - {x^2}yz{overrightarrow a _z}] Which of the following statements is TRUE?

The intensity of radiation of a dipole depends strongly on frequency. If at a frequency f, the intensity of radiation is '$$I$$' then at a frequency of $$frac{{ ext{f}}}{2}$$, the intensity will be:

A lossy transmission line has resistance per unit length-R = 0.01 Ω/m. The line is distortion less and has characteristic impedance of 100 Ω. The attenuation constant (in NP/m, correct to three decimal places) of the line is

A transmission line has a characteristic impedance of 50 Ω and a resistance of 0.1 Ω/m. If the line is distortion less, the attenuation constant (in Np/m) is

The inductance and energy stored in joules in the magnetic field of the solenoid having length 30 cm and diameter 3 cm and wound with 1000 turns of wire when carrying a current of 10 Amp.

Magnetic flux density is given by:

Tangential component of the electric field on perfect conductor will be

Lorentz's force law for a point charge q is given by:

Find, which statement is ""TRUE' for A vector field F I. Solenoidal and irrotational if ∇ ⋅ F = 0 and ∇ × F = 0 II. Solenoidal but not irrotational, if ∇ ⋅ F ≠ 0 and ∇ × F = 0 III. Irrotational but not solenoidal, if ∇ × F ≠ 0 and ∇ ⋅ F ≠ 0 IV. Neither solenoidal nor irrotational, if ∇ ⋅ F ≠ 0 and ∇ × F ≠ 0

If the electric field strength of a plane wave is 12 V/m. What will be the strength of magnetic field in free space-

According to Ampere's circuital Law the line integral of H about any closed path is exactly . . . . . . . . to the direct current enclosed by that path.

Consider an interface between two dielectric materials, one with ε r = 2 while the other has ε r = 5. If the tangential component of electric field on one side of the interface has a magnitude of 10 V.m -1 . What is the magnitude of the tangential component of electric field on the other side?

At a frequency of 1 GHz, the equivalent inductance between the terminals of a $$frac{lambda }{8}$$ (λ represents wavelength) short-circuited lossless 50 Ω line is

A plane electromagnetic wave travelling in a perfect dielectric medium of characteristic impedance η 1 is incident normally on its boundary with another perfect dielectric medium of characteristic impedance η 2 . The electric and magnetic field strengths of the incident wave are denoted by E 1 and H 1 respectively whereas E r and H r denote these quantities for the reflected wave, and E t and H t for the transmitted wave. Which of the following relations are correct? 1. E i = η 1 H i 2. E r = η 1 H r 3. E t = -η 2 H t Select the correct answer using the options given below:

A loop antenna is a commonly used for

Which antenna is a wideband antenna?

The potential that appears at a point in space due to the current which caused it is called potential

The minimum height of outer atmosphere is

The radiation pattern of a parabola antenna is

The virtual height of an ionospheric layer is __________ true height

The transmitting antennas for lower frequencies (below 500 kHz) are generally

Which of the following will increase the antenna radiation efficiency?

According to maximum power transfer theorem, the maximum power is absorbed by one network from another network when

Tropospheric scatter propagation is not subject to any fading.

A square corner reflector is used in which of the following?

In an impedance smith chart, a clockwise movement along a constant resistance circle gives rise to

In case of surface waves the field strength at a point is directly proportional to

The radiation pattern of Hertzian dipole in the plane perpendicular to dipole is a

In a perfect conductor the incident and reflected wave combine to produce

It is best to use for coupling a coaxial line to a parallel wire transmission line.

In H-plane metal plate lens the travelling wave front is

Which of the following is multiband HF receiving antenna?

An open wire transmission line having a characteristic impedance of 600 ohms is terminated by a resistive load of 900 O. The standing wave ratio will be

A conductor 4 m long lies along x-axis with a current of 10.0 A in the $${hat i}$$ direction. The force on this conductor due to a magnetic field $$B = 0.05hat kT$$ xa0 is

The value of $$oint {Dell } $$ xa0along a circle of radius 2 unit is

Which of the following is not Maxwell's equation for static electromagnetic field in isotropic and homogenous medium?

A copper rod of length L is rotated about one end perpendicular to the uniform magnetic field B with constant angular velocity ω. The induced emf between the two end is

Consider a closed surface S surrounding a volume V. If [overrightarrow r ] is the position vector of a point inside S, with [{hat n}] the unit normal on s, the value of the integral [mathop{{int!!!!!int}mkern-21mu x08igcirc}limits_S
{5overrightarrow r .hat ndS} ] xa0 is

Which of the following represents Maxwell's divergence equation for static electric field?

The depth of penetration is the depth in which electromagnetic wave has been attenuated to

Poisson's equation for inhomogeneous medium is:

A Geostationary satellite completes one orbit in

Divergence theorem is applicable for . . . . . . . .

Divergence of D is a

An axial magnetic field is applied to a cylindrical rod. The Faraday rotation of a plane polarized beam after emergence from the rod is 5°. If both the field and length of rod or doubled, then the angle of rotations is:

The force between two parallel current carrying conductors placed at a x distance apart and carrying same current I is :

The magnetic field inside the solenoid

If C is a closed curve enclosing a surface S, then the magnetic field intensity $$overrightarrow H $$, the current density $$overrightarrow J $$ and the electric flux density $$overrightarrow D $$ are related by

A uniform and constant magnetic field $$B = hat zB$$ xa0exists in the $$overrightarrow z $$ direction in vacuum. A particle of mass m with a small charge q is introduced into this region with an initial velocity $$v = hat x{v_x} + hat z{v_z}.$$ xa0 Given that B, m, q, v x and v z are all non-zero. Which one of the following describes the eventual trajectory of the particle?

Two capacitors C 1 = 20 µF and C 2 = 25 µF with respective breakdown voltages of V 1 = 50 V and V 2 = 40 V are given:

A quarter wave transformer can be used for matching accurately

In the relation between the field and the potential, if r < a, then the potential at a point r inside a uniformly charged sphere of radius a, is

A medium of relative permittivity ε r 2 = 2 form an interface with free-space. A point source of electromagnetic energy is located in the medium at depth of 1 meter from the interface. Due to the total internal reflection, the transmitted beam has a circular cross-section over the interface. The area of the beam cross-section at the interface is given by

Two ceramic capacitors have the following parameters. One has capacitance C 1 and ceramic thickness d 1 . The other has capacitance C 2 and ceramic thickness d 2 . When the two are connected in parallel, the combination has a capacitance of

The electric field component of a uniform plane wave propagating in a lossless magnetic dielectric medium is given by $$overrightarrow E left( {t,,z}
ight) = {{hat a}_x}5cos left( {{{10}^9}t - frac{{20}}{3}z}
ight){ ext{V/m}}{ ext{.}}$$ xa0 xa0 xa0 If η 0 represents the intrinsic impedance of the free space, the corresponding magnetic field component is given by

A small current carrying circular loop lies on a vertical plane. P is a point of observation on the orthogonal vertical plane passing through the centre of the loop and θ is the angle between O and OP as shown in the given figure. The θ component of the H-field will vary as:

Equation of the plane passing through the point [3overrightarrow i - overrightarrow j + overrightarrow k ] xa0 and perpendicular to the vector [4overrightarrow i + 2overrightarrow j - overrightarrow k ] xa0 is

The divergence of the magnetic flux density B is given as:

Consider the following statements regarding a plane wave propagating through free space: The direction of field 1. 'E' is perpendicular to the direction of propagation 2. 'H' is perpendicular to the direction of propagation 3. 'E' is perpendicular to the direction of field 'H' Which of these statements are correct?

A transmission line has characteristic impedance of 500 Ω. It has been terminated in a 200 Ω load. If the load is dissipating a continuous power of 100 W, its reflection coefficient is

Which of the following statement is correct?

Consider the following statements regarding impedance matching: 1. When the line is terminated in an impedance other than its characteristic impedance, reflection will occur and there will be standing waves of voltage and current along the line which may be very large if there is considerable mismatch. 2. The single-stub device has the advantage that it will match any load. 3. The double stub has the disadvantage that the line length needs to be adjustable. Which of the above statements are correct?

A 75 Ω transmission line is first short terminated and the minima locations are noted. When the short is replaced by a resistive load R L , the minima locations are not altered and the VSWR is measured to be 3. The value of R L is

Which one of the following Maxwell's equations gives the basic idea of radiation?

Which one of the following is the correct expression for torque on a loop in magnetic field $$overrightarrow B $$? (here $$overrightarrow M $$ is the loop moment).

The signal propagation time between two ground stations in a synchronous satellite link is about

A conductor having surface density σ is embedded in a dielectric medium of permittivity ε. The electric field in the medium is E. If it is known that the pressure p on the conductor surface is equal to the electric energy density in the medium, then p (in SI units) is given by:

A 50 Ω loss less transmission line is terminated in 100 Ω load and is exited by a 30 MHz source of internal resistance of 50 Ω. What should be the length of transmission line for maximum power transfer . . . . . . . .

A transmission - line impairment is located 300 m from the source. For a velocity of propagation of 0.9 c, the time elapsed from the beginning of the pulse to reception of the echo is

S parameters of a transmission line are S 11 , S 12 , S 21 and S 22 . If the transmission line is symmetrical, what is the condition?

For a reflection coefficient of 0.5, the value of SWR is

The electric field of a uniform plane electromagnetic wave in free space, along the positive x direction, is given by $$overrightarrow E = 10left( {{{hat a}_y} + j{{hat a}_z}}
ight){e^{ - j25x}}.$$ xa0 xa0 The frequency and polarization of the wave, respectively, are

If the magnitude of $$overrightarrow { ext{H}} $$ in a plane wave is 1 A/m, what is the magnitude of $$overrightarrow { ext{E}} $$ for a plane wave in free space:

The time averaged Poynting vector, in W/m 2 , for a wave with $$overrightarrow E = 24{e^{jleft( {omega t + Bz}
ight)}}{overrightarrow a _y}{ ext{V/m}}$$ in free space

In a medium if ε, µ, and σ are constant through out the medium, then it is known as:

If φ = 2x 2 y - xz 3 , then the Laplacian of φ is

The loss-less, quarter wavelength long, RF transmission of characteristic impedance 50 Ω is terminated in pure resistive load impedance 100 Ω, the input impedance is:

A loss-less 50 ohm transmission line is terminated in (A) 25 ohm and (B) 100 ohm loads. Which one of the following statements would be correct, if the voltage standing wave patterns measured in the two cases are compared?

The main components of atmosphere responsible for absorption of electromagnetic waves are

The region between two concentric cylinder with radii of 2 and 5 cm contains a volume charge distribution of -10 -8 (1 + 10r) C/m 3 . If E r and V both are zero at the inner cylinder and ε = ε 0 , the potential V at the outer cylinder will be:

Find the gradient of the curve y = 3x 2 -7x + 2 at the point (1, -2):

The characteristic impedance of a transmission line with inductance 0.294 µH/m and capacitance 60 pF/m, is

In a charge-free space, the Poisson's equation results in which of the following?

A TEM wave is incident normally upon a perfect conductor. The E and H fields at the boundary will be, respectively,

Two identical copper wires W 1 and W 2 placed in parallel as shown in the figure, carry currents I and 2I, respectively, in opposite directions. If the two wires are separated by a distance of 4r, then the magnitude of the magnetic field [overrightarrow B ] between the wires at a distance r from W 1 is

When a dielectric is placed in an electric field, the electric flux density D, electric field intensity E and polarization P are related as

Gilbert is a unit of

If $${vec a}$$ is a constant vector and $$vec r = xhat i + yhat j + zhat k,$$ xa0 xa0then div $$left( {vec a imes vec r}
ight)$$ xa0and curl $$left( {vec a imes vec r}
ight)$$ xa0are given by

A material is described by the following electrical parameters at a frequency of 10 GHz σ = 10 6 mho/m, µ = µ 0 and ∈/∈ 0 = 10. The martial at this frequency is considered to be $$left( {{ in _0} = frac{1}{{36pi }} imes {{10}^{ - 9}}{ ext{F/m}}}
ight)$$

For a perfect matched load the value of standing wave ratio and reflection coefficient respectively are

Laplace equation in cylindrical coordinates is given by:

A measure of the mismatch between the maximum and minimum voltage and current variation along the transmission line is called SWR, i.e. standing wave ratio. SWR indicates how much power is delivered to the load, and how much is lost in the line. When SWR is 1, the percent reflected power is zero. When SWR is 1.5, the percent reflected power will be

The electric field of an electromagnetic wave at a point in free space is in the positive Y direction and the magnetic field is in the negative X direction. The direction of power flow will be in the

The flux and potential functions due to a line charge and due to two concentric circular conductors are of the following form:

The continuity of the tangential field component at the interface of two media for normal incidence of a plane wave requires

Which of the following relationship correct

A point charge is located at origin. At point (a, a) electric field is E 1 . At point (-a, a) the electric field is E 2 and at point (-a, -a) the electric field is E 3 .

Which is valid Maxwell equation for magnetic flux density.

The electric field intensity $$overrightarrow E $$ at a point P is given by $$10hat i + 10hat j + 10hat k$$ xa0 xa0where $$hat i,,hat j$$ xa0and $${hat k}$$ are unit vectors in x, y and z directions respectively. If α, β, γ are respectively the angles the $$overrightarrow E $$ vector makes with x, y and z axes respectively, they are given by which of the following?

As a result of reflections from a plane conducting wall, electromagnetic waves acquire an apparent velocity greater than the velocity of light in space. This is called the

$${
abla ^2}H = {mu _0}{varepsilon _0}frac{{{partial ^2}overrightarrow H }}{{partial {t^2}}}$$ xa0 xa0is a

Consider the following statements: 1. For an isotropic medium, ε is a scalar constant. 2. For a homogeneous medium, ε, µ and σ are constant throughout the region. 3. In an anisotropic medium, D and E have the same direction. 4. For certain crystalline medium, ε varies with the direction of E. Which of the above crystalline medium, ε varies with the direction of E.

The magneto-motive force is

When the phase velocity of an electromagnetic wave depends on frequency in any medium, the phenomenon is called

Gauss theorem is expressed mathematically as:

"The surface integral of curl of a vector field over an open surface equals the line integral of the vector field over the closed curve bounding the surface area" this is the statement of-

A very reliable service has to be established between two points on earth separated by 1000 km. The band that will be used is

What is the magnitude of emf induced in a 200 turn coil with cross-sectional area of 0.16 m 2 , if the magnetic field through the coil changes from 0.10 Wb/m 2 to 0.50 Wb/m 2 at a uniform rate over a period of 0.02 seconds?

The characteristic impedance of a lossless transmission line is given by

Consider the following statements regarding the load matching and impedance measurements: 1. A mismatched load can be properly matched to a line by inserting prior to the load a transmission line $$frac{lambda }{4}$$ long. 2. For matching of 120 Ω load to a 75 Ω line, the quarter-wave transformer must have a characteristic impedance of 190 Ω. 3. The main disadvantage of single-stub matching is that it is a narrow-band or frequency-sensitive device. Which of the above statements are not correct?

What is the minimum value of VSWR that may exist on a transmission line?

The electric field around a positive charge is

An electromagnetic wave is transmitted into a conducting medium of conductivity ?. The depth of penetration is

What is the effect of the earth's magnetic field in the reflected wave at frequencies in the vicinity of gyro-frequency?

For free space E = 50 cos(10 8 t + βx), then the value of β . . . . . . . .

The value of flux linkage is 6t 3 at time t = 2 seconds. What is the emf of a material?

The depth of penetration of electromagnetic wave in a medium having conductivity σ at a frequency of 1 MHz is 25 cm. The depth of penetration at a frequency of 4 MHz will be

In a transmission line with ωL >> R and ωC >> G, Phase Shift constant β is proportional to

In electromagnetic waves, polarisation is

The line impedance at voltage minimum is

For a plane wave propagating in an unbounded medium (say, free space), the minimum angle between electric field and magnetic field vectors is

An infinitely long uniform charge of density 30 nC/m is located at y = 3, z = 5. The field intensity at (0, 6, 1) is E = 64.7a y - 86.3a z V/m. What is the field intensity at (5, 6, 1)?

Consider a solid sphere of radius 5 cm made of a perfect electric conductor. If one million electrons are added to this sphere, these electrons will be distributed:

The divergence of magnetic flux density is

A lossless transmission line is 100 cm long operate at 400 MHz. The line parameters are L = 0.49 µH/M and C = 100 pf. Find the phase constant and phase velocity.

Given a range of frequencies, which of the following system is best for transmission line load matching?

The dominant mode in a waveguide is characterized by

Electric displacement current density D at any point on a spherical surface of radius r centred at the isolated charge q is:

Due to polarization.

Magnetic flux can be measured by:

A theorem that relates surface integral with the volume integral is called

When a load resistance RL is connected to a lossless transmission line of characteristic impedance 75 Ω. It results in a VSWR of 2. The load resistance is

In a hundred-turn coil, if the flux through each turn is (t 3 - 2t) mWb, the magnitude of the induced emf in the coil at a time of 4s is:

A uniform plane electromagnetic wave incident normally on a plane surface of a dielectric material is reflected with a VSWR of 3. What is the percentage of incident power that is reflected?

Skin depth at 2 GHz for a gold conductor with σ = 4.55 × 10 7 S/m is 1.5 µm. Skin depth (in µm) at 8 GHz & 18 GHz is:

Which one of the following is caused by reflection from stratified atmosphere or from the surface or land conditions along the path?

Polarization of dielectric materials results in

The property of the material which oppose the creation of magnetic flux in it is called

The capacitor is made with a polymeric dielectric having an ε r of 2.26 and a dielectric breakdown strength of 50 KV/cm. The permittivity of free space is 8.85 pF/m. If the rectangular plates of the capacitor have a width of 20 cm and a length of 40 cm, then the maximum electric charge in the capacitor is

If R = Earth's radius, h = orbit height, β = coverage angle, and θ = minimum elevation angle, then which one of the following relations is correct?

The value of the determinant
[left| {x08egin{array}{*{20}{c}}
{cos heta }& heta &{sin heta } \
0&1&0 \
{ - sin heta }&0&{cos heta }
end{array}}
ight|] xa0xa0 is

The electric field component of a wave in free space is given by E = 50sin(10 7 t + kz)$${hat j}$$ V/m. Which one of the following is the correct inference that can be drawn from this expression?

The current flowing through a wire of length 2.5 cm is 100 A. If wire is bent into a square, magnetizing force at the centre of square is

If the potential, V = 4x + 2 volts, the electric field is:

Poynting vector P = E × H has the unit

Consider the following For a lossless transmission line, we can write: 1. Z in = -jZ 0 for a shorted line with $$l$$ = λ/8 2. Z in = ±j∞ for a shorted line with $$l$$ = λ/4 3. Z in = -jZ 0 for an open line with $$l$$ = λ/2 4. Z in = Z 0 for a matched line of any length Select the correct answer using the options given below:

VSWR of a purely resistive load of normalized value n + j0 for n < 1 is:

The wave length of a 100 MHz electromagnetic wave propagating through a perfect non-magnetic dielectric with relative permittivity ε r = 9 is

Match List-I with List-II for a transmission line with a series impedance Z = R + jωLΩ/m and a shunt admittance Y = G + jωC mho/m, and select the correct answer: List-I (Parameters) List-II (Values) a. Characteristic impedance Z 0 1. $$sqrt {{ ext{ZY}}} $$ b. Propagation constant γ 2. $$sqrt {frac{{ ext{Z}}}{{ ext{Y}}}} $$ c. The sending-end input impedance Z S when the line is terminated in its characteristic impedance Z 0 3. $$sqrt {frac{{ ext{Y}}}{{ ext{Z}}}} $$

Refraction of radio waves in the atmosphere results due to:

The electric field on the surface of a perfect conductor is 2 V/m. The conductor is immersed in water with ∈ = 80 ∈ 0 . The surface charge density on the conductor is $$left( { in = frac{{{{10}^{ - 9}}}}{{36pi }}}
ight){ ext{F/m}}$$

If [overrightarrow F left( {
ho ,,phi ,,z}
ight) =
ho {{hat a}_
ho } +
ho {sin ^2}phi {{hat a}_phi } - z{{hat a}_z}] xa0 xa0 xa0 which one of the following is TRUE?

Short circuited stubs are preferred to open-circuited stubs because the latter are

Two metal rings 1 and 2 are placed in a uniform magnetic field which is decreasing with time their planes perpendicular to the field. If the rings are identical except that ring 2 has a thin air gap in it, which one of the following statement is correct?

An electric charge of Q coulombs is located at the origin. Consider electric potential V and electric field intensity E at any point (x, y, z). Then

In the infinite plane y = 6m, there exists a uniform surface charge density of $$frac{1}{{6000pi }}mu { ext{C/}}{{ ext{m}}^2}$$ xa0 the associated electric field strength is

A plane wave having x-directed electric field propagating in free space along the z-direction is incident on an infinite electrically conducting (perfect conductor) sheet at z = 0 plane. Which one of the following is correct?

The capacitance per unit length and the characteristic impedance of a lossless transmission line are C and Z 0 respectively. The velocity of a travelling wave on the transmission line is

An infinite plane Z = 10 m carries a uniformly distributed charge of density 2n C/m 2 . The electric field intensity at the origin is

An elliptically polarized wave travelling in the positive Z-direction in air has x and y components E x = 3sin(ωt - βz) V/m
E y = 6sin(ωt - βz + 75°) V/m

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 Q 2 3. inversely proportional to A Of these statements which are correct?

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

The phase velocity of a plane wave given by E x = E 0 cos(ωt - βz) with a frequency of 5.0 GHz and a wavelength in the material medium of 3.0 cm is:

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 (E 0 is a constant)

A boundary separates two magnetic materials of permeability µ 1 and µ 2 . The magnetic field vector in µ 1 is H 1 with a normal component H n 1 and tangential component H t 1 while that in µ 2 is H 2 with normal component H n 2 and a tangential component H t 2 . Then the derived conditions would be

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-

An electromagnetic wave having frequency f 0 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 f 0 , after travelling the same distance d in the same conductor, the signal will get attenuated by a factor of:

The wave which 'lie down and dies' is called

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

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

High range resolution is obtained with

The input impedance of a short circuited lossless transmission line quarter wave long is

A loss-less line length x such that $$x08eta { ext{x}} = frac{pi }{2}$$ xa0 is connected in between a line of characteristic impedance of 100 Ω and a load impedance of 400 Ω. The line so connected should have a characteristic impedance of

Inside a hollow conducting sphere

If the maximum electron density for E layer in ionosphere is 9 × 10 6 electrons/cm 3 , then its critical frequency is

For a perfectly matched line the reflection coefficient has value of:

The electric field inside a metal is always . . . . . . . .

Impedance inversion may be obtained with-

Which of the following is correct?

Three point charges, Q 1 = 30 nC, Q 2 = -150 nC, and Q 3 = 70 nC, are enclosed by surface S. What net flux crosses S?

A transmission line is terminated at its characteristic impedance The reflection coefficient is

Given the electric field $$E = 2xhat i - 4yhat j{ ext{ V/m}}$$ xa0 xa0find the work done in moving a point charge of 2 C from (2, 0, 0)m to (0, 0, 0)m.

A transmission line of characteristic impedance 75 ohms is terminated with an impedance of 50 ohms. The line length is increased from zero. What will be the locus of the input impedance at the other end of the line? (N.B. : Reference impedance of Smith Chart = 50 Ohms)

For the vectors [overline A = x{{hat a}_x} + y{{hat a}_y}] xa0 and [overline B = z{{hat a}_z},,
abla .left( {overline A imes overline B }
ight)] xa0 xa0is

A conductor of length 1 m moves at right angles to a uniform magnetic field of flux density 2 Wb/m 2 with a velocity of 50 m/s. What is the value of the induced e.m.f. when the conductor moves at an angle of 30° to the direction of the field?

The parallel-plate capacitor shown in the figure has movable plates. The capacitor is charged so that the energy stored in it is E when the plate separation is d. The capacitor is then isolated electrically and the plates are moved such that the plate separation becomes 2d. At this new plate separation what is the energy stored in the capacitor, neglecting fringing effects?

The solutions to many problems involving electric fields are simplified by making use of equipotential surfaces. An equipotential surface is a surface: 1. On which the potential is same everywhere 2. The movement of charge over such a surface would require no work 3. The tangential electric field is zero 4. The normal electric field is zero Which of the above statements are correct?

Two identical coaxial coils carry the same current I but in opposite directions. The magnitude of the magnetic field B at a point on the axis midway between the coils is

Consider a transmission line of characteristic impedance 50 ohms and the line is terminated at one end by +j50 ohms, the VSWR produced in the transmission line will be

If the maximum and minimum voltages on a transmission line are 4 V and 2 V respectively, for a typical load, VSWR is

When a plane wave traveling in free space is incident normally on a medium having ε r = 4.0, the fraction of power transmitted into the medium is given by

Insertion loss is defined by

A TEM wave impinges obliquely on a dielectric-dielectric boundary with ∈ r 1 = 2 and
∈ r 2 = 1. The angle of incidence for total reflection is:

Which one of these equation is not Maxwell's equation for a static electromagnetic field in a linear homogeneous medium state?

In the following figure, the transmitter T x sends a wideband modulated RF signal via a coaxial cable to the receiver R x . The output impedance Z T of T x the characteristic impedance Z 0 of the cable and the input impedance Z R or R x are all real. Which one of the following statements is True about the distortion of the received signal due to impedance mismatch?

The equation ∇.J = 0 is known as:

A plane electromagnetic wave in a free space is represented by an equation.

A transmission line having characteristic impedance 'Z t ' of varying length in series with a load impedance 'Z L ' appears in a Smith Chart on:

When the target lies at such a distance from the radar that the radar receives the echo while it is transmitting, the target is said to be

What is the magnetic field intensity vector $$overrightarrow H $$ between two parallel sheets with separation 'd' along z-axis both sheets carrying surface current $$overline k = {k_y}{overline a _y}?$$

If over the course of a day, the maximum electron density in the ionosphere varies from 10 11 to 10 12 m -3

the critical frequency changes approximately from:

The value of ∇.A
where [A = 3xy{overrightarrow a _x} + x{overrightarrow a _y} + xyz{overrightarrow a _z}] xa0 xa0 at a point (2, -2, 2) is:

The divergence of a vector is a scalar, while the curl of a vector is another