MCQOPTIONS
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MCQOPTIONS
This section includes 1085 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 251. |
A toroid is _________ solenoid. |
| A. | a long |
| B. | a small |
| C. | not a |
| D. | none of these |
| Answer» B. a small | |
| 252. |
At _______ frequencies, RLC resonant circuits are replaced byelectromagnetic cavity resonators. |
| A. | Low |
| B. | Medium |
| C. | High |
| D. | None of these |
| Answer» D. None of these | |
| 253. |
The relative permittivity of free space is given by |
| A. | 1 |
| B. | 10 |
| C. | 100 |
| D. | 1000 |
| Answer» C. 100 | |
| 254. |
A cable or a wire is considered as a transmission line if its length is _________of the wavelength of the signal travelling through it. |
| A. | Greater than 1/10 |
| B. | Less than 1/10 |
| C. | Greater than 1/5 |
| D. | Less than 1/5 |
| Answer» B. Less than 1/10 | |
| 255. |
Wave number has units of____________. |
| A. | Radians |
| B. | Meter |
| C. | Radians/meter |
| D. | None of these |
| Answer» D. None of these | |
| 256. |
Two plates of parallel plate capacitor after being charged from a constant voltage source are separated apart by means of insulated handles, then the |
| A. | Voltage across the plates inceases |
| B. | Voltage across the plates decreases |
| C. | Charge on the capacitor decreases |
| D. | Charge on the capacitor increases |
| Answer» C. Charge on the capacitor decreases | |
| 257. |
The Smith chart is a ________ dimensional representation ofcomplex impedances with respect to coordinates. |
| A. | Two |
| B. | Three |
| C. | Four |
| D. | None of these |
| Answer» D. None of these | |
| 258. |
(AB) is equal to ___________. |
| A. | A. B |
| B. | A + B |
| C. | 2AB |
| D. | B A + A B |
| Answer» E. | |
| 259. |
In the case of an ideal isotropic antenna, the geometric radiationpattern is___________. |
| A. | Circle |
| B. | Sphere |
| C. | Parabola |
| D. | Hyperbola |
| Answer» C. Parabola | |
| 260. |
“ the total electric flux through any closed surface surroundingcharges is equal to the amount of charge enclosed “. |
| A. | Coulomb’s square law |
| B. | Gauss’s law |
| C. | Maxwell’s first law |
| D. | Maxwell’s second law |
| Answer» C. Maxwell’s first law | |
| 261. |
In the TEM mode, Ez ______ and Hz =_______ |
| A. | 0, 0 |
| B. | 0, ∞ |
| C. | ∞, 0 |
| D. | None of these |
| Answer» B. 0, ∞ | |
| 262. |
In the TM mode, Ez _____ and Hz = ________. |
| A. | 0, 0 |
| B. | 0, ∞ |
| C. | ∞ 0 |
| D. | None of these |
| Answer» E. | |
| 263. |
At the Brewster angle, polarization ______________. |
| A. | Cannot be reflected |
| B. | Is reflected at 30° |
| C. | Is reflected at 90° |
| D. | None of these |
| Answer» B. Is reflected at 30° | |
| 264. |
A vector P in Cartesian coordinates is represented by ____________. |
| A. | (Px, Pφ, Pz) |
| B. | (Px, Py, Pz) |
| C. | (Px, Pφ, Pθ) |
| D. | none of these |
| Answer» C. (Px, Pφ, Pθ) | |
| 265. |
Power density has _________________. |
| A. | A DC component |
| B. | A second harmonic component |
| C. | Both (a) and (b) |
| D. | None of these |
| Answer» D. None of these | |
| 266. |
On the basis of the radiation pattern, an antenna array is__________. |
| A. | Broadside |
| B. | End fire |
| C. | Either (a) or (b) |
| D. | None of these |
| Answer» D. None of these | |
| 267. |
Divergence of vector field is net outward flux of a vector per unit ______. |
| A. | surface area |
| B. | volume |
| C. | length |
| D. | none of these |
| Answer» C. length | |
| 268. |
If two vectors are orthogonal, then their scalar product is__________. |
| A. | 1 |
| B. | 0 |
| C. | ∞ |
| D. | 100 |
| Answer» C. ∞ | |
| 269. |
Insulators have their conductivity "σ" _________. |
| A. | >>1 |
| B. | <<1 |
| C. | none of these |
| Answer» C. none of these | |
| 270. |
Cartesian coordinates are represented in terms of ___________. |
| A. | (r, φ, z) |
| B. | (r, θ, φ) |
| C. | (x, y, z) |
| D. | all of these |
| Answer» D. all of these | |
| 271. |
The force between two charges is 120 N. If the distance between thecharges is doubled, the force will be |
| A. | 60 N |
| B. | 30 N |
| C. | 40 N |
| D. | 15 N |
| Answer» C. 40 N | |
| 272. |
The electric field intensity at a point situated 4 metres from a pointcharge is 200 N/C. If the distance is reduced to 2 metres, the field intensity will be |
| A. | 400 N/C |
| B. | 600 N/C |
| C. | 800 N/C |
| D. | 1200 N/C |
| Answer» D. 1200 N/C | |
| 273. |
The ability of charged bodies to exert force on 6ne another isattributed to the existence of |
| A. | electrons |
| B. | protons |
| C. | neutrons |
| D. | electric field |
| Answer» E. | |
| 274. |
Steady magnetic fields are governed by __________ law. |
| A. | Biot–Savart's |
| B. | Ampere's Circuital |
| C. | Both (a) and (b) |
| D. | None of these |
| Answer» D. None of these | |
| 275. |
If three 10 uF capacitors are connected in parallel, the net capacitance is |
| A. | 20 uF |
| B. | 30 uE |
| C. | 40 uF |
| D. | 50 uF |
| Answer» C. 40 uF | |
| 276. |
In empty space, conduction current is __________. |
| A. | Infinity |
| B. | Unity |
| C. | Zero |
| D. | None of these |
| Answer» D. None of these | |
| 277. |
Antenna gain is minimum at radiation pattern___________. |
| A. | Side lobes |
| B. | Back lobes |
| C. | None of these |
| D. | Gain is independent of the radiation pattern |
| Answer» B. Back lobes | |
| 278. |
Transmitters used on vehicles are__________ polarized. |
| A. | Linearly |
| B. | Circularly |
| C. | Both (a) and (b) |
| D. | None of these |
| Answer» C. Both (a) and (b) | |
| 279. |
Capacitor stores energy in _________ field. |
| A. | electric |
| B. | magnetic |
| C. | gravity |
| D. | none of these |
| Answer» B. magnetic | |
| 280. |
The unit of electric instensity is |
| A. | N/C2 |
| B. | Wb/m2 |
| C. | N/C |
| D. | N2/C |
| Answer» C. N/C | |
| 281. |
At the point of discontinuity, __________ component of magnetic fluxdensity is continuous. |
| A. | Tangential |
| B. | Normal |
| C. | None of these |
| D. | Cannot say |
| Answer» C. None of these | |
| 282. |
Dielectric stregth______with increasing thickness |
| A. | increases |
| B. | decreases |
| C. | remains unaltered |
| D. | none of the above |
| Answer» C. remains unaltered | |
| 283. |
A unit vector has _______ direction to that of the main vector. |
| A. | same |
| B. | opposite |
| C. | normal upwards |
| D. | normal downwards |
| Answer» B. opposite | |
| 284. |
The number of Faraday tubes of flux passing through a surface in anelectric field is called |
| A. | electric flux |
| B. | electric flux density |
| C. | magnetic flux density |
| D. | electric charge density |
| Answer» B. electric flux density | |
| 285. |
Maxwell's equations involve_______. |
| A. | Charge density |
| B. | Current density |
| C. | Magnetic intensity |
| D. | All of these |
| Answer» E. | |
| 286. |
A single core cable used on 33000 V has conductor diameter 10 mm and the in¬ternal diameter of sheath 25 mm. The maximum electrostatic stress in the cable is |
| A. | 62 x 105 V/m |
| B. | 72 x 105 V/m |
| C. | 82 x 105 V/m |
| D. | 92 x 105 V/m |
| Answer» C. 82 x 105 V/m | |
| 287. |
____________ product of two unit vectors is the third unit vector. |
| A. | vector |
| B. | scalar |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» B. scalar | |
| 288. |
Smith charts depict a wide impedance range of transmitter for _______VSWR. |
| A. | Low |
| B. | High |
| C. | Medium |
| D. | None of these |
| Answer» C. Medium | |
| 289. |
_______ velocity is the one at which loss of constant phase propagatesdown the guide. |
| A. | Medium |
| B. | Phase |
| C. | Group |
| D. | None of these |
| Answer» C. Group | |
| 290. |
Resonant frequency of an antenna depends upon its___________. |
| A. | Physical length |
| B. | Electrical length |
| C. | None of these |
| D. | Cannot say |
| Answer» C. None of these | |
| 291. |
Electric polarization of a material is electric dipole moment per unit _________. |
| A. | length |
| B. | area |
| C. | volume |
| D. | none of these |
| Answer» C. volume | |
| 292. |
Ampere's Circuital Law is analogous to __________ Law inelectrostatics. |
| A. | Lenz's |
| B. | Gauss's |
| C. | Biot–Savart's |
| D. | Faraday's |
| Answer» C. Biot–Savart's | |
| 293. |
According to the method of images, the tangential component ofelectric field to conductor surface is __________. |
| A. | Unity |
| B. | Zero |
| C. | Infinity |
| D. | None of these |
| Answer» C. Infinity | |
| 294. |
For making a capacitor , it is better to select a dielectric having |
| A. | Low permittivity |
| B. | High permittivity |
| C. | Permittivity same as that of air |
| D. | Permittivity slightly more than that of air |
| Answer» C. Permittivity same as that of air | |
| 295. |
Laplacian of a scalar is __________. |
| A. | scalar |
| B. | vector |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» B. vector | |
| 296. |
For a medium to be a quasi-conductor, the dissipation factor shouldbe _________. |
| A. | infinity |
| B. | zero |
| C. | unity |
| D. | none of these |
| Answer» D. none of these | |
| 297. |
The units of capacitance area |
| A. | volts/coulomb |
| B. | coulombs/volt |
| C. | ohms |
| D. | henry/Wb |
| Answer» C. ohms | |
| 298. |
Stoke's Theorem relates, ______ integral to a _______ integral. |
| A. | volume, surface |
| B. | volume, line |
| C. | line, surface |
| D. | all of these |
| Answer» D. all of these | |
| 299. |
'r' in Cylindrical coordinates corresponding to Cartesian coordinate(3, 4, 5) is ____________. |
| A. | 12 |
| B. | 7 |
| C. | 10 |
| D. | 5 |
| Answer» E. | |
| 300. |
Which of the following capacitors will have the least variation ? |
| A. | Paper capacitor |
| B. | Ceramic capacitor |
| C. | Silver plated mica capacitor |
| D. | None of the above |
| Answer» D. None of the above | |