MCQOPTIONS
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MCQOPTIONS
This section includes 595 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.
| 301. |
The field pattern of a solenoid is similar to that of bar magnet. |
| A. | 1 |
| B. | |
| C. | Both A and R are true and R is correct explanation of A |
| D. | Both A and R are true but R is not correct explanation of A |
| Answer» B. | |
| 302. |
An iron specimen has µr = 1000 when B = 0.3 T. If B = 0.35 T, µr |
| A. | will be 1000 |
| B. | will be less than 1000 |
| C. | will be more than 1000 |
| D. | may be more or less than 1000 |
| Answer» E. | |
| 303. |
If the operating temperature increases by 10°C, the rate of deterioration of solid dielectric becomes |
| A. | double |
| B. | one and a half time |
| C. | 3 times |
| D. | 4 times |
| Answer» B. one and a half time | |
| 304. |
The hysteresis loss is |
| A. | proportional to frequency |
| B. | independent of frequency |
| C. | proportional to (frequency)2 |
| D. | proportional to |
| Answer» B. independent of frequency | |
| 305. |
Silicon and germanium are elements in the |
| A. | fourth column of periodic table |
| B. | fifth column of periodic table |
| C. | 106 / cm3 |
| D. | 108 / cm3 |
| Answer» D. 108 / cm3 | |
| 306. |
Assertion (A): Copper is a monoatomic solid.Reason (R): In a metal the valence electrons belong to all atoms. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 307. |
A parallel plate capacitor has area of plate equal to 1 m and distance between plates is also 1 m2. The lossy dielectric has a complex dielectric constant ‚ààr = ‚àà'r - j ‚àà"r. If the capacitor is represented by R and C is parallel, then |
| A. | |
| B. | |
| Answer» B. | |
| 308. |
The charge per proton is |
| A. | 1.6 x 10-19 C |
| B. | 2.6 x 10-19 C |
| C. | 0.6 x 10-19 C |
| D. | 1.6 x 10-13 C |
| Answer» B. 2.6 x 10-19 C | |
| 309. |
The number of valence electrons in acceptor impurity are |
| A. | 5 |
| B. | 4 |
| C. | 3 |
| D. | 1 |
| Answer» D. 1 | |
| 310. |
Assertion (A): Ferromagnetic materials possess ferromagnetic properties only when temperature is less than paramagnetic curie temperature.Reason (R): For a ferromagnetic material for T > θf. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not correct explanation of A | |
| 311. |
As the viscosity of a liquid increases, the relaxation time |
| A. | remains constant |
| B. | increases |
| C. | decreases |
| D. | first decreases then increases |
| Answer» C. decreases | |
| 312. |
Assertion (A): An amorphous material is obtained when mobility of atoms is inhibited during solidification. Reason (R): Crystalline state is a natural state for most solids. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 313. |
The merger of hole and free electron is called |
| A. | covalent bonding |
| B. | recombination |
| C. | thermal energy |
| D. | free electrons |
| Answer» C. thermal energy | |
| 314. |
Which of the following is the poorest conductor of electricity? |
| A. | Aluminium |
| B. | Nichrome |
| C. | Copper |
| D. | All of the above |
| Answer» C. Copper | |
| 315. |
Assertion (A): In ionic dielectrics, P = Pe + Pi.Reason (R): In ionic crystals, permanent electric dipole moment is zero. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not correct explanation of A | |
| 316. |
Consider the following statement: In case of a superconductor B = 0μr is highdiamagnetism is hightransition temperature varies with isotopic mass. Of the above statements |
| A. | 1 and 2 are correct |
| B. | 2, 3, 4 are correct |
| C. | 1, 3, 4 are correct |
| D. | 2, 4 are correct |
| Answer» D. 2, 4 are correct | |
| 317. |
The relation between thermal conductivity K (W/m/°C), heat flow density Q (watt/m2) and dT/dx (°C per metre) is |
| A. | Q = K(dT/dx) |
| B. | Q = - K(dT/dx) |
| C. | K = Q(dT/dx) |
| D. | dT/dx = - QK |
| Answer» C. K = Q(dT/dx) | |
| 318. |
Assertion (A): ‚àà0 has the dimensions of farad per meter.Reason (R): D = ‚àà0‚ààr E. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 319. |
If q is charge on an electron, R is radius of electron orbit and ω is angular velocity of electron rotation, the magnetic dipole moment of electron in orbit is |
| A. | 0.5 qωR |
| B. | 0.5 q2ω2R2 |
| C. | 0.5 qωR2 |
| D. | 0.5 qω2R |
| Answer» D. 0.5 qœâ2R | |
| 320. |
Spontaneous polarization occurs in ferroelectric materials. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 321. |
Assertion (A): In a conductor, current density remains constant in time as long as E is constant.Reason (R): In a conductor, J = σE. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not correct explanation of A | |
| 322. |
A parallel plate capacitor having C = 200 x 10-12 F has loss dielectric having tan δ = 4 x 10-4. At an ac voltage of f = 106 Hz and peak value 2 V, the dielectric losses are |
| A. | 10-8 W |
| B. | 10-6 W |
| C. | 10-4 W |
| D. | 10-2 W |
| Answer» C. 10-4 W | |
| 323. |
For a diamagnetic material, μr = 1. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 324. |
In a metal, the drift velocity of electrons in the presence of a electric field E is |
| A. | proportional to E |
| B. | proportional to E |
| C. | inversely proportional to E |
| D. | proportional to E2 |
| Answer» B. proportional to E | |
| 325. |
In an homogeneous dielectric subjected to an electric field E, the dipole moment per unit volume is ‚àà0(‚ààr - 1) E. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 326. |
Assertion (A): For a magnetic material M = (μr - 1) H, where M is magnetic dipole moment/m3, H is field intensity A/m and μr is relative permeability.Reason (R): μr can have any value from 0 to hundreds of thousands. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» D. A is false but R is true | |
| 327. |
In a ferromagnetic material, the internal field seen by a dipole is |
| A. | equal to applied field |
| B. | equal to applied field minus a contribution from neighbouring dipoles |
| C. | equal to applied field plus a contribution from neighbouring dipoles |
| D. | equal to or less than applied field |
| Answer» D. equal to or less than applied field | |
| 328. |
For an insulating material, dielectric strength and dielectric losses should be |
| A. | high and high |
| B. | low and high |
| C. | high and low |
| D. | low and low |
| Answer» D. low and low | |
| 329. |
At 0 K, silicon and germanium behave like monoatomic crystals. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 330. |
The number of valence electrons in germanium atom is |
| A. | 4 |
| B. | 2 |
| C. | 1 |
| D. | zero |
| Answer» B. 2 | |
| 331. |
When the atom of rare gas is placed in an electric field the nucleus shifts from the centre of electron cloud by an amount x. If the radius of electron cloud is R, then |
| A. | x << R |
| B. | x 0.5 R |
| C. | x ‚âÖ 0.75 R |
| D. | x ‚âÖ R |
| Answer» B. x 0.5 R | |
| 332. |
If Bmax is the maximum flux density, eddy current loss is proportional to |
| A. | Bmax |
| B. | B1.6max |
| C. | B2max |
| D. | B3max |
| Answer» B. B1.6max | |
| 333. |
Consider the following materials NickelSilverOxygenAluminium The correct sequence in the order of decreasing permeability is |
| A. | 1, 4, 3, 2 |
| B. | 1, 4, 2, 3 |
| C. | 4, 1, 3, 2 |
| D. | 4, 1, 2, 3 |
| Answer» C. 4, 1, 3, 2 | |
| 334. |
The colour code on a carbon resistor is yellow-violet-orange. The value of resistance is |
| A. | 17000 Ω |
| B. | 27000 Ω |
| C. | 37000 Ω |
| D. | 47000 Ω |
| Answer» E. | |
| 335. |
Assertion (A): Electronic polarizability increases as atoms becomes larger.Reason (R): For rare gas, ‚àà0(‚ààr - 1) E = Nae, where N is number of atoms/m3 and ae is electronic polarizability of material. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 336. |
A parallel plate capacitor has area of plate A and plate separation d. Its capacitance is C. A metallic plate P of area A and negligible thickness is added as shown in Figure. The new value of capacitance is |
| A. | C |
| B. | 2C |
| C. | 0.5 C |
| D. | 0.25 C |
| Answer» B. 2C | |
| 337. |
Resistivity of metals consists of two parts, one part constant and the other temperature dependent. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 338. |
The resistance of a photoconductor |
| A. | increases with increase in light intensity |
| B. | decreases with increase in light intensity |
| C. | may increase or decrease with increase in light intensity |
| D. | remains constant |
| Answer» C. may increase or decrease with increase in light intensity | |
| 339. |
In terms of classical representation of electrons |
| A. | an atom is essentially empty |
| B. | an atom is essentially full |
| C. | an atom may be essentially empty or full depending on the material |
| D. | an atom may be essentially empty or full depending on temperature |
| Answer» B. an atom is essentially full | |
| 340. |
Piezoelectricity means the slight change in dimensions of a specimen when an electric field is applied. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 341. |
For a photoconductor with equal electron and hole mobilities and perfect ohmic contacts at the ends, an increase in intensity of optical illumination results in |
| A. | a change in o.c voltage |
| B. | a change in s.c current |
| C. | decrease in resistance |
| D. | increase in resistance |
| Answer» D. increase in resistance | |
| 342. |
When temperature is more than ferromagnetic curie temperature, the behaviour of a ferromagnetic material is similar to that of paramagnetic material. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 343. |
If WF is the Fermi level, then in a metal at T = 0 |
| A. | all energy levels above WF filled, all those below WF are empty |
| B. | all energy levels below WF are filled, all those above WF are empty |
| C. | some energy levels, both below and above WF, are filled |
| D. | all energy levels below and above WF are filled |
| Answer» C. some energy levels, both below and above WF, are filled | |
| 344. |
The orientation polarization of a polyatomic gas is inversely proportional to absolute temperature. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 345. |
The induced magnetic dipole moment is independent of the permanent magnetic dipole moment. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 346. |
A piece of copper and another piece of Germanium are cooled from 30°C to 80 K. The resistance of |
| A. | copper decreases and germanium increases |
| B. | both decreases |
| C. | both increases |
| D. | copper increases and germanium decreases |
| Answer» B. both decreases | |
| 347. |
We can know the arrangement of atom in a material by studying electron diffraction pattern. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 348. |
If μp is permanent dipole moment and T is absolute temperature, the orientation polarization of polyatomic gases is |
| A. | proportional to μp2T |
| B. | proportional to |
| C. | proportional to μp T |
| D. | proportional to |
| Answer» C. proportional to Œºp T | |
| 349. |
The v-i relation for an arc is v = 44 + . If v = 50 V, i = |
| A. | 0.41666666666667 |
| B. | 0.20833333333333 |
| C. | 0.083333333333333 |
| D. | 0.5 A |
| Answer» C. 0.083333333333333 | |
| 350. |
The electric dipole moment of a neutral system of point charges Q1, Q2.... is Qiri . The charges Qi |
| A. | must be all positive |
| B. | must be all negative |
| C. | must be such that Qi = 0 |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |