MCQOPTIONS
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MCQOPTIONS
This section includes 9294 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1551. |
The direction in a Yagi Uda antenna is longer than the radiating element. |
| A. | True |
| B. | False |
| Answer» C. | |
| 1552. |
If wave of critical frequency 30 MHz is departing at an angle of 60 , then the MUF is given to be |
| A. | 10 MHz |
| B. | 15 MHz |
| C. | 30 MHz |
| D. | 60 MHz |
| Answer» E. | |
| 1553. |
An antenna having an effective temperature of 27 K is fed into a microwave amplifier that has an effective noise temperature of 30 K. Calculate the available noise power per unit bandwidth |
| A. | 30 K |
| B. | 57 K |
| C. | 27 K |
| D. | 3K, K is Boltzmann constant |
| Answer» C. 27 K | |
| 1554. |
The length of half-wave antenna is at 30 MHz |
| A. | 2.5 meter |
| B. | 5 meter |
| C. | 10 meter |
| D. | 100 meter |
| Answer» C. 10 meter | |
| 1555. |
For a 400 kHz transmission line having L = 0.5 mH/km, C = 0.08 mF and negligible R and G, the characteristic impedance will be |
| A. | 14 Ω |
| B. | 28 Ω |
| C. | 39 Ω |
| D. | 79 Ω |
| Answer» E. | |
| 1556. |
A broadside array consisting of 200 cm wavelength with 10 half-wave dipole spacing 10 cm. And if each array element feeding with 1 amp. current and operating at same frequency then find the radiated power |
| A. | 730 W |
| B. | 73 W |
| C. | 100 W |
| D. | None |
| Answer» B. 73 W | |
| 1557. |
Two identical and parallel dipole antenna are kept apart by a distance of /4 in the H-plane. They are fed with equal currents but the right most antenna has a phase shift of + 90 . The radiation pattern is given as |
| A. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/203-416-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/203-416-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/203-416-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/203-416-4.png"> |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/203-416-2.png"> | |
| 1558. |
For a 400 kHz transmission line having L = 0.5 mH/km, C = 0.08 mF and negligible R and G, the velocity propagation will be |
| A. | 15.8303 km/s |
| B. | 15.830 km/s |
| C. | 1.583 km/s |
| D. | 0.1583 km/s |
| Answer» B. 15.830 km/s | |
| 1559. |
Antenna efficiency of antenna is, if radiation resistance is 370 &ohm; and loss resistance is 100 &ohm; |
| A. | 80% |
| B. | 87% |
| C. | 78% |
| D. | 21.27% |
| Answer» D. 21.27% | |
| 1560. |
Divergence of curl A is |
| A. | . ( x A) = 1 |
| B. | . ( x A) = 0 |
| C. | . ( x A) = |
| D. | . ( x A) = - |
| Answer» C. . ( x A) = | |
| 1561. |
Calculate the directivity of a given linear end fire, uniform array of 20 element, each separated by /3 |
| A. | 100 |
| B. | 10 |
| C. | 26.66 |
| D. | 30 |
| Answer» D. 30 | |
| 1562. |
The effective length of an /2 antenna (Given Rr = 73 &ohm; and (Ae)max = 0.13 2 and = 120 p is __________ . |
| A. | 0.6348 |
| B. | 0.317 |
| C. | 0.158 |
| D. | 0.371 |
| Answer» C. 0.158 | |
| 1563. |
If reflection coefficient is 1/5, then corresponding VSWR is given by |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 3/2 |
| Answer» E. | |
| 1564. |
The thin parallel wires are carrying current along the same direction. The force experienced by one due to the other is |
| A. | parallel to the lines |
| B. | perpendicular to the lines and attractive |
| C. | perpendicular to the lines and repulsive |
| D. | zero |
| Answer» C. perpendicular to the lines and repulsive | |
| 1565. |
Which of following antenna does not depend upon the frequency? |
| A. | Log-periodic |
| B. | Parabolic |
| C. | Conical |
| D. | All of the above |
| Answer» B. Parabolic | |
| 1566. |
Mutual impedance is not depend upon |
| A. | magnitude of induced current |
| B. | tuning condition |
| C. | self impedance |
| D. | phase relationship between induced and original currents |
| Answer» D. phase relationship between induced and original currents | |
| 1567. |
A material has conductivity of 10-2 mho/m and a relative permittivity of 4. The frequency at which conduction current in the medium is equal to displacement current is |
| A. | 45 MHz |
| B. | 90 MHz |
| C. | 450 MHz |
| D. | 900 MHz |
| Answer» B. 90 MHz | |
| 1568. |
A transmission line is feeding 1 watt of power to a horn antenna having a gain of 10 dB. The antenna is matched to the transmission line. The total power radiated by the horn antenna into the free space is |
| A. | 10 watt |
| B. | 1 watt |
| C. | 0.1 watt |
| D. | 0.01 watt |
| Answer» B. 1 watt | |
| 1569. |
An end fire array consisting of several half-wave lengths of directive gain 40, then find the width of major lobe |
| A. | 60 |
| B. | 50 |
| C. | 51.25 |
| D. | None of the above |
| Answer» D. None of the above | |
| 1570. |
A uniform plane EM wave incident normally on a plane surface of a dielectric material is reflected with a VSWR of 3. What percentage of incident power that is reflected? |
| A. | 10% |
| B. | 25% |
| C. | 50% |
| D. | 75% |
| Answer» C. 50% | |
| 1571. |
Poynting vector is associated with which of the following? |
| A. | Power flow in electromagnetic |
| B. | Flux in magnetic field |
| C. | Charge in electrostatic field |
| D. | Current in electrostatic field |
| Answer» B. Flux in magnetic field | |
| 1572. |
When the phase velocity of an EM wave depends on frequency in any medium, the phenomenon is called |
| A. | scattering |
| B. | polarization |
| C. | absorption |
| D. | dispersion |
| Answer» C. absorption | |
| 1573. |
Beamwidth (between first nulls) will be for an antenna at 3 MHz with directivity of 100 |
| A. | 140 |
| B. | 70 |
| C. | 210 |
| D. | 60 |
| Answer» B. 70 | |
| 1574. |
In which of the following is the width of junction barrier very small? |
| A. | Tunnel diode |
| B. | Photo diode |
| C. | PIN diode |
| D. | Schottky diode |
| Answer» E. | |
| 1575. |
Assertion (A): When Diode used as rectifier the reverse breakdown voltage should not be exceeded. Reason (R): A high inverse voltage can destroy a p-n junction. |
| 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 a 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 a correct explanation of A | |
| 1576. |
Which of the following is not a key word in C? |
| A. | pop |
| B. | for |
| C. | if |
| D. | union |
| Answer» B. for | |
| 1577. |
Consider the following statements about an array in Pascal An array has a fixed predetermined number of components.Any component of an array can be accessed using an index.An array variable name refers to a group of quantities by a single name.When array variables are used an appropriate declaration is required. Which of the above are correct? |
| A. | All |
| B. | 1, 2, 3 only |
| C. | 2, 3, 4 only |
| D. | 1, 2 and 4 only |
| Answer» B. 1, 2, 3 only | |
| 1578. |
A computer program is used to read M and print the sum 2 + 4 + 6 + 8 +.........+ 2M. If M = 9 , the print out will show the number |
| A. | 9 |
| B. | 18 |
| C. | 90 |
| D. | 100 |
| Answer» D. 100 | |
| 1579. |
If F = 95.0 what will be the result of following FORTRAN 77 program? REAL F , CREAD * , FC = (5. / 9.) * (F - 32.) |
| A. | 35.0 |
| B. | 35 |
| C. | 25.0 |
| D. | 25 |
| Answer» B. 35 | |
| 1580. |
Consider the following expressions in Java int a, b, c, a = 40;b = a++ ;c = ++a ;Now the values of a, b, c are |
| A. | 42, 40, 42 respectively |
| B. | 42, 42, 42 respectively |
| C. | 40, 42, 42 respectively |
| D. | 40, 40, 42 respectively |
| Answer» B. 42, 42, 42 respectively | |
| 1581. |
Assertion (A): In C arithmetic operations are pemiissible on ints, floats and chars.Reason (R): In C every arithmetic operator must be written explicitly. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 1582. |
The standard FORTRAN exponential form of decimal number - 0.000000023 is |
| A. | 2.3 E - 8 |
| B. | -2.3 E - 8 |
| C. | 2.3 E - 7 |
| D. | -2.3 E - 7 |
| Answer» C. 2.3 E - 7 | |
| 1583. |
Which of the following methods does not cause any reduction in instruction length? |
| A. | Using program counter |
| B. | Common source and destination address |
| C. | Implicit source and destination address |
| D. | Machine language programming |
| Answer» E. | |
| 1584. |
The number of primitive string operations in 8086 is |
| A. | 3 |
| B. | 4 |
| C. | 5 |
| D. | 6 |
| Answer» D. 6 | |
| 1585. |
Assertion (A): In microprocessor 8085 instruction LXIB, 90 FF H means register B and C are loaded with upper and lower bytes to get B = 90 H and C = FFH.Reason (R): In 8085 the stack pointer indicates which memory location is to accessed. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 1586. |
The word size accessible at a time from the memory subsystem depends on |
| A. | width of data bus |
| B. | width of address bus |
| C. | width of control bus |
| D. | both (b) and (c) |
| Answer» B. width of address bus | |
| 1587. |
The initial contents of ACC and CY in 8085 are CY = 1ACC = 10000001 After instruction RAL is executed once the contents of CY and ACC respectively will be |
| A. | 1 and 00000011 |
| B. | 0 and 00000011 |
| C. | 1 and 00000001 |
| D. | 0 and 00000001 |
| Answer» B. 0 and 00000011 | |
| 1588. |
RAM is a volatile memory device. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 1589. |
8085 data bus has 8 lines and is bidirectional. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 1590. |
A PC has typically |
| A. | 5 to 10 KB of main memory |
| B. | 10 to 100 KB of main memory |
| C. | 100 to 256 KB of main memory |
| D. | 256 KB to 1 MB of main memory |
| Answer» E. | |
| 1591. |
Read the following statement Multi-processing operation permits highly efficient parallel processing at several levels.Multi processing involves use of several processing units jointly on a common program and severally on different programs.In multi-processing the assignment of facilities to tasks, loading of programs and monitoring of I/O activity is taken care of by operating system. Which of the above are correct? |
| A. | All |
| B. | 1 and 2 only |
| C. | 1 and 3 only |
| D. | 2 and 3 only |
| Answer» B. 1 and 2 only | |
| 1592. |
Which memory has read operation, byte erase, byte write and chip erase? |
| A. | RAM |
| B. | UVEPROM |
| C. | EEPROM |
| D. | both (b) and (c) |
| Answer» D. both (b) and (c) | |
| 1593. |
In a typical microcomputer data transfer takes place between |
| A. | P and memory |
| B. | P and I/O devices |
| C. | memory and I/O devices |
| D. | all of the above |
| Answer» E. | |
| 1594. |
The use of microprocessor control in automobiles results in |
| A. | improved fuel economy |
| B. | improved car control |
| C. | advanced information system for driver |
| D. | all of the above |
| Answer» E. | |
| 1595. |
Assertion (A): Structures are useful in DBMS.Reason (R): Structures are very large numbers of applications besides DBMS. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 1596. |
Which one is correct option? |
| A. | TEM mode exist in free space of infinite boundary |
| B. | TEM mode exist in two conductor pattern system for finite-boundary |
| C. | TEM mode exist in waveguide only |
| D. | Both (a) and (b) |
| Answer» E. | |
| 1597. |
The electric flux and field intensity inside a conducting sphere is |
| A. | minimum |
| B. | maximum |
| C. | uniform |
| D. | zero |
| Answer» E. | |
| 1598. |
For a plane good conductor, skin depth varies |
| A. | directly as square root of permeability |
| B. | directly as square root of frequency |
| C. | inversely as permittivity |
| D. | inversely as square root of conductivity |
| Answer» E. | |
| 1599. |
For broadside array, maxima will be obtain at |
| A. | 90 , 270 |
| B. | 180 |
| C. | 45 |
| D. | at any angle |
| Answer» B. 180 | |
| 1600. |
The length of a /2 antenna in feet is given by the relation |
| A. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/210-572-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/210-572-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/210-572-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/210-572-4.png"> |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/210-572-2.png"> | |