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This section includes 247 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
201. |
The modes of propagation supported by a rectangular wave guide is: |
A. | tm, tem, te modes |
B. | tm, te |
C. | tm, tem |
D. | te, tem |
Answer» C. tm, tem | |
202. |
For TE1â‚’ mode, if the waveguide is filled with air and the broader dimension of the waveguide is 2 cm, then the cutoff frequency is: |
A. | 5 mhz |
B. | 7.5 mhz |
C. | 7.5 ghz |
D. | 5 ghz |
Answer» D. 5 ghz | |
203. |
The major advantage of double stub tuning is: |
A. | it uses 2 tuning stubs in fixed positions |
B. | it involves 2 stubs |
C. | length of the stub is variable |
D. | none of the mentioned |
Answer» B. it involves 2 stubs | |
204. |
In a double stub tuner circuit, the load is of _______ length from the first stub. |
A. | fixed length |
B. | arbitrary length |
C. | depends on the load impedance to be matched |
D. | depends on the characteristic impedance of the transmission line |
Answer» C. depends on the load impedance to be matched | |
205. |
The major disadvantage of single stub tuning is: |
A. | it requires a variable length of line between the load and the stub |
B. | it involves 2 variable parameters |
C. | complex calculation |
D. | none of the mentioned |
Answer» B. it involves 2 variable parameters | |
206. |
The reflection coefficient of a transmission line having characteristic and load impedances as 50 and 30 ohm respectively is |
A. | 1/4 |
B. | 1/8 |
C. | 1/2 |
D. | 3/4 |
Answer» B. 1/8 | |
207. |
Calculate the transmission coefficient, when the incident and transmitted amplitudes are 10 and 7 respectively. |
A. | 17 |
B. | 3 |
C. | 10/7 |
D. | 0.7 |
Answer» E. | |
208. |
Find the characteristic impedance of a quarter wave with input and load impedances given by 50 and 25 respectively. |
A. | 50 |
B. | 25 |
C. | 75 |
D. | 35.35 |
Answer» E. | |
209. |
Which of the following parameters does not exist in the transmission line equation? |
A. | r |
B. | zo |
C. | zl |
D. | propagation constant |
Answer» B. zo | |
210. |
Which primary parameter is uniformly distributed along the length of the conductor? |
A. | g |
B. | c |
C. | l |
D. | r |
Answer» E. | |
211. |
The lowest mode of TE mode propagation in a circular waveguide is: |
A. | te10 mode |
B. | te00 mode |
C. | te01 mode |
D. | te11 mode |
Answer» D. te11 mode | |
212. |
When a λ/4 transmission line is used for impedance matching, then which of the following is valid? |
A. | standing waves are present on the λ/4 transmission line |
B. | no standing waves on the λ/4 transmission line |
C. | standing waves are not present both on the feed line and the matching λ/4 line |
D. | standing waves are present on both the feed line and the matching λ/4 line |
Answer» B. no standing waves on the λ/4 transmission line | |
213. |
If there is no standing wave on a transmission line, then the value of SWR is: |
A. | 1 |
B. | 0 |
C. | infinity |
D. | insufficient data |
Answer» B. 0 | |
214. |
Expression for the characteristic impedance of a transmission line(λ/4) used for impedance matching is: |
A. | z1=√(zₒr)l |
B. | z1=√(zₒ/r)l |
C. | z1=√(zₒ+r)l |
D. | none of the mentioned |
Answer» B. z1=√(zâ‚’/r)l | |
215. |
maintain at safe limit. |
A. | average current |
B. | average voltage |
C. | average bias voltage |
D. | average resistance |
Answer» B. average voltage | |
216. |
an IMPATT diode, it results in: |
A. | avalanche multiplication |
B. | break down of depletion region |
C. | high reverse saturation current |
D. | none of the mentioned |
Answer» B. break down of depletion region | |
217. |
The mode of operation in which the Gunn diode is not stable is: |
A. | gunn oscillation mode |
B. | limited space charge accumulation mode |
C. | stable amplification mode |
D. | bias circuit oscillation mode |
Answer» B. limited space charge accumulation mode | |
218. |
GaAs is used in fabricating Gunn diode. Gunn diode is: |
A. | bulk device |
B. | sliced device |
C. | made of different type of semiconductor layers |
D. | none of the mentioned |
Answer» B. sliced device | |
219. |
GaAs is used in the fabrication of GUNN diodes because: |
A. | gaas is cost effective |
B. | it less temperature sensitive |
C. | it has low conduction band electrons |
D. | less forbidden energy gap |
Answer» E. | |
220. |
The material out of which PIN diode is made is: |
A. | silicon |
B. | germanium |
C. | gaas |
D. | none of the mentioned |
Answer» B. germanium | |
221. |
A major disadvantage of klystron amplifier is: |
A. | low power gain |
B. | low bandwidth |
C. | high source power |
D. | design complexity |
Answer» C. high source power | |
222. |
The phase and group velocities does not depend on which of the following? |
A. | frequency |
B. | wavelength |
C. | phase constant |
D. | attenuation constant |
Answer» E. | |
223. |
Which of the following parameter is non zero for a lossless line? |
A. | attenuation |
B. | resistance |
C. | conductance |
D. | phase constant |
Answer» E. | |
224. |
reflector electrode after the cavity. |
A. | backward wave oscillator |
B. | reflex klystron |
C. | travelling wave tube |
D. | magnetrons |
Answer» C. travelling wave tube | |
225. |
amplifier. |
A. | linear beam |
B. | crossed field |
C. | parallel field |
D. | none of the mentioned |
Answer» B. crossed field | |
226. |
The propagation constant for a lossless transmission line will be |
A. | real |
B. | complex |
C. | real and equal to phase constant |
D. | complex and equal to phase constant |
Answer» E. | |
227. |
In transverse electric waves, which of the following is true? |
A. | e is parallel to h |
B. | e is parallel to wave direction |
C. | e is transverse to wave direction |
D. | h is transverse to wave direction |
Answer» D. h is transverse to wave direction | |
228. |
The dominant mode in rectangular waveguide is |
A. | te01 |
B. | te10 |
C. | tm01 |
D. | tm10 |
Answer» C. tm01 | |
229. |
The cut off frequency for a waveguide to operate is |
A. | 3 mhz |
B. | 3 ghz |
C. | 6 mhz |
D. | 6 ghz |
Answer» E. | |
230. |
In rectangular waveguides, the dimensions a and b represent the |
A. | broad wall dimensions |
B. | broad wall and side wall dimension respectively |
C. | side wall and broad wall dimension respectively |
D. | side wall dimensions |
Answer» C. side wall and broad wall dimension respectively | |
231. |
range of |
A. | hz |
B. | khz |
C. | mhz |
D. | ghz |
Answer» E. | |
232. |
For the matched line, the parameters S12 and S21 are |
A. | 1 |
B. | 0 |
C. | -1 |
D. | ∞ |
Answer» C. -1 | |
233. |
The waveguides are materials with characteristics of |
A. | low bulk resistivity |
B. | high bulk resistivity |
C. | high conductivity |
D. | low conductivity |
Answer» B. high bulk resistivity | |
234. |
The scattering parameters are used to indicate the |
A. | permittivity and permeability |
B. | electric and magnetic field intensities |
C. | reflection and transmission coefficients |
D. | frequency and wavelength |
Answer» D. frequency and wavelength | |
235. |
The circular waveguides use which function in the frequency calculation? |
A. | laplace function |
B. | schottky function |
C. | bessel function |
D. | transfer function |
Answer» D. transfer function | |
236. |
The modes are calculated from which parameter? |
A. | frequency |
B. | wavelength |
C. | phase constant |
D. | v number |
Answer» E. | |
237. |
The dominant mode in waveguide is the mode which has |
A. | highest frequency |
B. | highest wavelength |
C. | lowest phase constant |
D. | highest attenuation |
Answer» C. lowest phase constant | |
238. |
The best stub selection for the transmission line will be |
A. | series open |
B. | series short |
C. | shunt open |
D. | shunt short |
Answer» E. | |
239. |
respectively. The standing wave ratio is |
A. | 2 |
B. | 3 |
C. | 1/2 |
D. | 4 |
Answer» C. 1/2 | |
240. |
The phenomenon employed in the waveguide operation is |
A. | reflection |
B. | refraction |
C. | total internal reflection |
D. | adsorption |
Answer» D. adsorption | |
241. |
Identify the material which is not present in a transmission line setup. |
A. | waveguides |
B. | cavity resonator |
C. | antenna |
D. | oscillator |
Answer» E. | |
242. |
The characteristic impedance of a transmission line is normally chosen to be |
A. | 50 |
B. | 75 |
C. | 50 or 75 |
D. | 100 |
Answer» D. 100 | |
243. |
The average power in an electromagnetic wave is given by |
A. | propagation constant |
B. | pointing vector |
C. | phase constant |
D. | attenuation constant |
Answer» C. phase constant | |
244. |
For a matched line, the input impedance will be equal to |
A. | load impedance |
B. | characteristic impedance |
C. | output impedance |
D. | zero |
Answer» C. output impedance | |
245. |
wave ratio of 2.5 is |
A. | 20 |
B. | 125 |
C. | 200 |
D. | 75 |
Answer» C. 200 | |
246. |
ohm is |
A. | 50 |
B. | 20 |
C. | 1000 |
D. | 125 |
Answer» E. | |
247. |
. Which of the following parameters is not a primary parameter? |
A. | resistance |
B. | attenuation constant |
C. | capacitance |
D. | conductance |
Answer» C. capacitance | |