📡 Electronics and Communication Engineering (ECE) Solved MCQs with Answers

Practice 406 approved 📡 Electronics and Communication Engineering (ECE) questions with verified answers from the 🛠️ Engineering Essentials subject for Pakistan exams.

406 solved MCQs

A stepper motor isAnswer: is an electromechanical device which actuates a train of step angular movements in response to a train of input pulses on one to one basis From the noise point of view, bandwidth shouldAnswer: not be too large When a unit step voltage drives a lag network the outputAnswer: increases exponentially from zero to final value A system has its two poles on the negative real axis and one pair of poles lies on jω axis. The system isAnswer: limitedly stable Bellows convertsAnswer: pressure difference into displacement Assertion (A): The steady state response, of a stable, linear, time invariant system, to sinusoidal input depends on initial conditions. Reason (R): Frequency response, in steady state, is obtained by replacing s in the transfer function by jωAnswer: R is correct but A is wrong The phase margin and damping ratio have no relation.Answer: False The log magnitude curve for a constant gain K is aAnswer: horizontal straight line of magnitude 20 log K decibels A lag compensator is essentially aAnswer: low pass filter Stepper motors find applications inAnswer: all of the above In an integral controllerAnswer: the rate of change of output is proportional to input Bode magnitude plot is drawn betweenAnswer: dB magnitude and log ω In a minimum phase systemAnswer: all zeros lie in the left half plane A cordless telephone using separate frequencies for transmission in base and portable units is known asAnswer: duplex arrangement What will be the Beta factor in common emitter configuration of transistor, if it's alpha factor is 1/2?Answer: 1 If the turns ratio of a transformer is 5, the secondary voltage is greater than the primary voltage by factor _____?Answer: 5 Energy density in case of a capacitor is always proportional to _____?Answer: E² (Square of electric intense between plates) The microscopic form of Ohm's law ____?Answer: J = σE How many acres are there in one hectare?Answer: 2.47 In Compton scattering from stationary electrons the largest change in wavelength occurs when the proton is scattered through _____?Answer: 180° Find lim x → 1^+ (2 + √x - 1) = ?Answer: Voltage gain of the amplifier Germanium is a semiconductor.Answer: True Optical fiber operates on the principle of ______?Answer: Total internal reflectance What is the range of frequencies in which AM radio operates?Answer: 550 to 1700 KHz The control in SCADA is_________?Answer: Supervisory control The wavelength of the radio waves having 90 MHz frequency is?Answer: 3.33 m The long-distance carrier system provided in the ___________ and throughout the world is designed to transmit voice band signals over high-capacity transmission links, such as coaxial cable and microwave systems.Answer: USA A combinational circuit consists ofAnswer: All of these Binary logic resembles binary arithmetic and the operations AND and OR have some similarities to ______________, respectively.Answer: Multiplication and addition Analog data in electrical form __________ transmitted as baseband signals.Answer: Can be