Explore topic-wise MCQs in Electromagnetic Theory.

This section includes 248 Mcqs, each offering curated multiple-choice questions to sharpen your Electromagnetic Theory knowledge and support exam preparation. Choose a topic below to get started.

201.

The time average Poynting vector in W/m

A. <table><tr><td rowspan="2">-<br></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>2.4</center></td><td> </td><td rowspan="2"><br>a<sub>z</sub></td></tr> <tr><td style="text-align: center;"> </td></tr> </table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>2.4</center></td><td> </td><td rowspan="2"><br>a<sub>z</sub></td></tr><br><tr><td style="text-align: center;"> </td></tr><br></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>4.8</center></td><td> </td><td rowspan="2"><br>a<sub>z</sub></td></tr><br><tr><td style="text-align: center;"> </td></tr><br></table>
D. <table><tr><td rowspan="2"> - </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>4.8</center></td><td> </td><td rowspan="2"><br>a<sub>z</sub></td></tr><br><tr><td style="text-align: center;"> </td></tr><br></table>
Answer» B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>2.4</center></td><td> </td><td rowspan="2"><br>a<sub>z</sub></td></tr><br><tr><td style="text-align: center;"> </td></tr><br></table>
Discussion
202.

Intrinsic impedance of copper at high frequencies is

A. Purely resistive
B. Purely inductive
C. Complex with capacitive component
D. Complex with an inductive component
Answer» E.
Discussion
203.

A parabolic dish antenna has a conical beam 2 wide. The directivity of the antenna is approximately

A. 20 dB
B. 30 dB
C. 40 dB
D. 50 dB
Answer» E.
Discussion
204.

A (75 j 50) load is connected to coaxial transmission line of Z

A. A short circuited stub at the load
B. An inductance at the load
C. A capacitance at some specific distance from the load
D. A short circuited stub at some specific distance from the load
Answer» E.
Discussion
205.

Assuming the velocity of EM waves reaching an antenna as 3 10

A. 7.5 m
B. 13 m
C. 30 m
D. 60 m
Answer» E.
Discussion
206.

Some unknown material has a conductivity of 10

A. 15.9 m
B. 20.9 m
C. 25.9 m
D. 30.9 m
Answer» B. 20.9 m
Discussion
207.

A km long microwave link uses two antennas each having 30 dB gain. If the power transmitted by one antenna is 1 W at 3 GHz. Power received by the other antenna is approximately

A. 98.6 W
B. 76.8 W
C. 63.4 W
D. 55.2 W
Answer» D. 55.2 W
Discussion
208.

Critical frequency of ionospheric layer is 10 MHz what is the maximum launching angle from the horizon for which 20 MHz wave will be reflected by the layer?

A. 0
B. 30
C. 45
D. 90
Answer» C. 45
Discussion
209.

A uniform plane wave in air is normally incident on infinitely thick slab, if the refractive index of the glass slab is 1.5 then the percentage of incident power that is reflected from the air glass interface is

A. 0%
B. 4%
C. 20%
D. 100%
Answer» C. 20%
Discussion
210.

A metal sphere with 1 m radius and a surface charge density of 10 coulomb/m2 is enclosed in a cube of 10 m side. The total outward electric displacement normal to the surface of the cube is

A. 40 coulombs
B. 10 coulombs
C. 5 coulombs
D. None of these
Answer» E.
Discussion
211.

A 300 line is terminated in a load impedance of 100 + j 200 the voltage reflection coefficient is

A. 0.6325 108
B. 0.7 30
C. 0.27 + j 0.196
D. 0.377 42.7
Answer» B. 0.7 30
Discussion
212.

In order to receive a vertically polarized wave the conductor of the dipole should be mounted

A. Horizontally
B. Vertically
C. At an angle of 45
D. None of these
Answer» C. At an angle of 45
Discussion
213.

Radiation resistance of a monopole of height h = l/2 is given by

A. &sime; 400 (h )
B. <sup>2</sup>
C. <table><tr><td rowspan="2">&amp;sime; 400<br></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td>2</td></tr><tr><td style="text-align: center;">h</td></tr></table>
D. <table><tr><td rowspan="2">&amp;sime; 400<br></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>h</center></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td>2</td></tr><tr><td style="text-align: center;"> </td></tr></table>
E. <table><tr><td rowspan="2">&amp;sime; 200<br></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td>2</td></tr><tr><td style="text-align: center;">h</td></tr></table>
Answer» D. <table><tr><td rowspan="2">&amp;sime; 400<br></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>h</center></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td>2</td></tr><tr><td style="text-align: center;"> </td></tr></table>
Discussion
214.

In a broadside array of 20 isotropic radiators equally spaced at a distance of /2. The beamwidth between first nulls is

A. 51.3 degrees
B. 11.46 degrees
C. 22.9 degrees
D. 102.6 degrees
Answer» C. 22.9 degrees
Discussion
215.

A radiowave is incident on a layer of ionosphere at an angle of 30 degree with the vertical common. If the critical frequency is 1.2 MHz the maximum usable frequency is

A. 1.2 MHz
B. 2.4 MHz
C. 0.6 MHz
D. 1.386 MHz
Answer» E.
Discussion
216.

When a wave is propagated in a good dielectric where / << 1 the attenuation factor and the phase shift factor are given by

A. <table><tr><td rowspan="2"> = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2"> <span style=" text-decoration: overline;"></span></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2">, = <span style=" text-decoration: overline;"> </span></td></tr><tr><td style="text-align: center;">2</td><td style="text-align: center;"> </td></tr></table>
B. <table><tr><td rowspan="2"> = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2">, = <span style=" text-decoration: overline;"> </span></td></tr><tr><td style="text-align: center;">2</td></tr></table>
C. <table><tr><td rowspan="2"> = </td> <td rowspan="2"> <span style=" text-decoration: overline;"></span></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2"> <span style=" text-decoration: overline;"></span></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2">, = </td><td rowspan="2"> <span style=" text-decoration: overline;"></span></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td></tr><tr><td style="text-align: center;">2 </td><td style="text-align: center;"> </td><td style="text-align: center;">2</td></tr></table>
D. = 1, = 45
Answer» B. <table><tr><td rowspan="2"> = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2">, = <span style=" text-decoration: overline;"> </span></td></tr><tr><td style="text-align: center;">2</td></tr></table>
Discussion
217.

For a short wave radio link between two stations via the ionosphere. The ratio of the maximum usable frequency to the critical frequency

A. Is always less than 1
B. Is always greater than 1
C. May be less than or more than 1 depending on the distance between the two stations
D. Does not depend on the distance between the two stations
Answer» C. May be less than or more than 1 depending on the distance between the two stations
Discussion
218.

Two dissimilar antennas having their maximum directivities equal

A. Must have their beamwidth also equal
B. Cannot have their beamwidth equal because they are dissimilar antennas
C. May not necessarily have their maximum power gains equal
D. Must have their effective apertures areas (capture areas) also equal
Answer» D. Must have their effective apertures areas (capture areas) also equal
Discussion
219.

An antenna having resonant frequency f and having a Q factor of 20 can handle a bandwidth of 10 MHz then f is

A. 10 MHz
B. 20 MHz
C. 200 MHz
D. None of these
Answer» D. None of these
Discussion
220.

The electric field component of a uniform plane electromagnetic wave propagating in the y-direction in a lossless medium will satisfy the equation

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> <sup>2</sup>E<sub>y</sub></center></td><td rowspan="2">= </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> <sup>2</sup>E<sub>y</sub></center></td></tr><tr><td style="text-align: center;"> y<sup>2</sup></td><td style="text-align: center;"> t<sup>2</sup></td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> <sup>2</sup>E<sub>y</sub></center></td><td rowspan="2">= </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> <sup>2</sup>E<sub>y</sub></center></td></tr><tr><td style="text-align: center;"> y<sup>2</sup></td><td style="text-align: center;"> t<sup>2</sup></td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> <sup>2</sup>E<sub>x</sub></center></td><td rowspan="2">= </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> <sup>2</sup>E<sub>x</sub></center></td></tr><tr><td style="text-align: center;"> y<sup>2</sup></td><td style="text-align: center;"> t<sup>2</sup></td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> <span style=" text-decoration: overline;">E<sup>2</sup>x +E<sup>2</sup>z</span></center></td><td rowspan="2"> = </td><td rowspan="2"> <span style=" text-decoration: overline;"></span></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td></tr><tr><td style="text-align: center;"> <span style=" text-decoration: overline;">H<sup>2</sup><sub>x</sub> </span>+ H<sup>2</sup><sub>z</sub></td><td style="text-align: center;"> </td></tr></table>
E. Both A and D
Answer» F.
Discussion
221.

In a reflex Klystron oscillator

A. The maximum possible efficiency is about 58%.
B. The frequency of oscillation varies linearly with the reflector voltage.
C. The power output varies continuously with reflector voltage.
D. The power output is maximum at fixed frequency.
E. Both A and B
Answer» F.
Discussion
222.

Maximum gain of antenna using an illuminated 6 feet paraboloid reflector used at 6 MHz will be

A. 1008
B. 8050
C. 950
D. 428
Answer» C. 950
Discussion
223.

Radiation resistance of a current element of length dl is

A. <table><tr><td rowspan="2"> 80</td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> dl</center></td><td rowspan="2"> <img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td>2</td><td rowspan="2"> ohms</td></tr><tr><td style="text-align: center;"> </td></tr></table>
B. <table><tr><td rowspan="2"> 80 </td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>dl</center></td><td rowspan="2"> <img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td>2</td><td rowspan="2"> ohms</td></tr><tr><td style="text-align: center;"> </td></tr></table>
C. <table><tr><td rowspan="2"> 80</td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> dl</center></td><td rowspan="2"> <img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td>2</td><td rowspan="2"> ohms</td></tr><tr><td style="text-align: center;"> </td></tr></table>
D. <table><tr><td rowspan="2"> 80</td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>dl</center></td><td rowspan="2"> <img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td>2</td><td rowspan="2"> ohms</td></tr><tr><td style="text-align: center;">2</td><td style="text-align: center;"> </td></tr></table>
Answer» C. <table><tr><td rowspan="2"> 80</td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> dl</center></td><td rowspan="2"> <img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td>2</td><td rowspan="2"> ohms</td></tr><tr><td style="text-align: center;"> </td></tr></table>
Discussion
224.

The depth of velocity modulation in a two cavity Klystron amplifier can be increased by increasing the

A. Amplitude of the applied signal voltage
B. Beam coupling coefficient
C. Cavity gap transit angle
D. Catcher d.c. voltage
E. Both A and B
Answer» F.
Discussion
225.

In the infinite plane y = 6 m there exists a uniform surface charge density of

A. 30 i V/m
B. 30 j V/m
C. 30 k V/m
D. 60 i V/m
Answer» D. 60 i V/m
Discussion
226.

The electric field strength at a distance point P due to a point charge +q located on the origins is 100 V/m if the point charge is now enclosed by a perfectly conducting metal sheet sphere whose centre is at origin then the electric field strength at the point P outside the sphere becomes

A. Zero
B. 100 V/m
C. 100 V/m
D. 50 V/m
Answer» C. 100 V/m
Discussion
227.

The beamwidth between first null of uniform linear array of N equally spaced (element spacing = a) equally excited antennas is determined by

A. N alone and not by a
B. d alone and not by N
C. The ratio (N/d)
D. The product (Nd)
Answer» E.
Discussion
228.

An open wire transmission line has primary constant

A. 169.73 , 25
B. 238.2 , 25
C. 715 , 25
D. 50 , 25
Answer» B. 238.2 , 25
Discussion
229.

Length of dipole can be calculated from the relationship

A. <table><tr><td rowspan="2"> = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>5000</center></td></tr><tr><td style="text-align: center;">f</td></tr></table>
B. <table><tr><td rowspan="2"> = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>500</center></td></tr><tr><td style="text-align: center;">f<sup>2</sup></td></tr></table>
C. <table><tr><td rowspan="2"> = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>462</center></td></tr><tr><td style="text-align: center;">f</td></tr></table>
D. <table><tr><td rowspan="2"> = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>c</center></td></tr><tr><td style="text-align: center;">f</td></tr></table>
Answer» C. <table><tr><td rowspan="2"> = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>462</center></td></tr><tr><td style="text-align: center;">f</td></tr></table>
Discussion
230.

The shortest stub length in required to produce a reactance equal to Z

A.
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td></tr><tr><td style="text-align: center;">8</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td></tr><tr><td style="text-align: center;">4</td></tr></table>
D. 2
Answer» C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td></tr><tr><td style="text-align: center;">4</td></tr></table>
Discussion
231.

A beam antenna consists of a dipole one reflector and one director. The velocity factor is 0.90 and antenna is to be cut for a frequency of 150 MHz. The length of the dipole will be

A. 0.4 m
B. 0.5 m
C. 0.9 m
D. 1.2 m
Answer» D. 1.2 m
Discussion
232.

Choose the correct statements:

A. Waveguide wavelength is never less than the free space wavelength.
B. Wave impedance is never less than the free space impedance.
C. Phase velocity is never less than the free space velocity.
D. TEM mode is possible if the dimensions of the waveguide are properly chosen.
Answer» D. TEM mode is possible if the dimensions of the waveguide are properly chosen.
Discussion
233.

The height of a transmitting antenna is 225 m above the ground level. Its radio horizon will be

A. 60 km
B. 76 km
C. 120 km
D. 225 km
Answer» B. 76 km
Discussion
234.

A line with lumped parameters of series resistance 10 shunt resistance is composed of 200 . 10 T sections matched to a generator with an emf of 3 volts and terminated by its characteristic impedance. The current at the sending end of the line is

A. 24.4 A
B. 0.066 A
C. 0.033 A
D. 0.0033 A
Answer» C. 0.033 A
Discussion
235.

Medium wave radio signals may be received at for distance at night because

A. Radiowaves travel faster at night
B. Ground wave attenuation is low at night
C. The sky wave is stronger at night
D. Their is no fading at night
Answer» D. Their is no fading at night
Discussion
236.

A material is described by following electrical parameters as a frequency of 10 GHz, = 10

A. A good conductor
B. A good dielectric
C. Neither a good conductor nor a good dielectric
D. A good magnetic material
Answer» B. A good dielectric
Discussion
237.

For a wire radiator of length equal to the wavelength of the transmitting signal. The number of loops in the radiation pattern will be

A. 1
B. 2
C. 3
D. 4
Answer» E.
Discussion
238.

In a multicavity magnetron strapping is employed primarily

A. To prevent mode jumping
B. To increase the separation between the resonant frequencies in the -mode and in the adjacent mode
C. To reduce the back heating of the cathode
D. To increase the output of the magnetron
E. Both A and B
Answer» F.
Discussion
239.

A transmission line whose characteristic impedance is a pure resistance

A. Must be a lossless line
B. Must be a distortion line
C. May not be a lossless line
D. May not be a destortionless line
E. Both A and B
Answer» F.
Discussion
240.

The ground wave coverage of the medium wave transmitter is 100 km and in the height the first reflected ray is at 800 km. The skip distance is

A. 900 km
B. 700 km
C. 100 km
D. 800 km
Answer» C. 100 km
Discussion
241.

The incoming solar radiation at a place on the surface of the earth is 1.2 kw/m

A. 80 m V/m
B. 2.5 V/m
C. 30 V/m
D. 950 V/m
Answer» E.
Discussion
242.

The radiation pattern of a folded dipole antenna is of the form

A. <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/Capture-5.png">
B. <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/Capture-5-2.png">
C. <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/Capture-5-3.png">
D. <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/Capture-5-4.png">
Answer» D. <img src="http://images.interviewmania.com/wp-content/uploads/2019/05/Capture-5-4.png">
Discussion
243.

A quarter wave transformer matches a 100 ohm load to a transmission line with L = 1.35 H/m and C = 60 pFm. The characteristic impedance of matching transformer is

A. 150
B. 122.5
C. 275
D. 300
Answer» C. 275
Discussion
244.

The radiation resistance of a /16 wire dipole in free space will be nearly

A. 1
B. 3
C. 13
D. 30
Answer» C. 13
Discussion
245.

The length of a /2 antenna in feet is given by the relation

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2">= </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>468</center></td></tr><tr><td style="text-align: center;">2</td><td style="text-align: center;">f(MHz)</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2">= </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>492</center></td></tr><tr><td style="text-align: center;">2</td><td style="text-align: center;">f(MHz)</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2">= </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>192</center></td></tr><tr><td style="text-align: center;">2</td><td style="text-align: center;">f(MHz)</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2">= </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>150</center></td></tr><tr><td style="text-align: center;">2</td><td style="text-align: center;">f(MHz)</td></tr></table>
Answer» B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td><td rowspan="2">= </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>492</center></td></tr><tr><td style="text-align: center;">2</td><td style="text-align: center;">f(MHz)</td></tr></table>
Discussion
246.

Two isotropic antennas are separated by a distance of two wavelength if both the antennas are fed with currents of equal phase and magnitude. The number of lobes in the radiation pattern in the horizontal plane are

A. 2
B. 4
C. 6
D. 8
Answer» B. 4
Discussion
247.

Which of the following field equations show that free magnetic charges do not exist?

A. <table><tr><td rowspan="2">H = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>1</center></td><td rowspan="2">( A)</td></tr><tr><td style="text-align: center;"> </td></tr></table>
B. <table><tr><td rowspan="2">H = </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>IdI r</center></td><td rowspan="2">4 R<sup>2</sup></td></tr><tr><td style="text-align: center;"> </td></tr></table>
C.
D. .H = 0
E. H = J
Answer» D. .H = 0
Discussion
248.

Characteristic impedance of a quarter wave transformer connected in between a load of 100 and a transmission line of characteristic impedance 225 ohms is

A. 100
B. 225
C. 600
D. 150
Answer» E.
Discussion