Explore topic-wise MCQs in Engineering.

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.

4251.

Which of the following memories normally has highest storage capacity?

A. Magnetic disc
B. Magnetic tape
C. Semiconductor memory
D. Core memory
Answer» B. Magnetic tape
4252.

The number of comparators of needed in a parallel conversion type 8 bit A to D converter is

A. 8
B. 16
C. 255
D. 256
Answer» D. 256
4253.

11012 - 10012 =

A. 1000
B. 0100
C. 0010
D. 0001
Answer» C. 0010
4254.

A master slave flip-flop has the characteristics that

A. change in the I/P immediately reflected in the O/P
B. change in the O/P occurs when the state of the master is affected
C. change in the output occurs when the state of the slave is affected
D. both the master and the slave states are affected at the same time
Answer» D. both the master and the slave states are affected at the same time
4255.

Least expensive logic

A. RTL
B. DTL
C. TTL
D. ECL
Answer» B. DTL
4256.

Which of the following flip-flops is used as latch?

A. JK flip-flop
B. D flip-flop
C. RS flip-flop
D. T flip-flop
Answer» D. T flip-flop
4257.

The circuit show in the figure has 4 boxes each described by inputs P, Q, R and outputs y, z withY = P Q R, Z = RQ + PR + QP The circuit act as a

A. 4 bit adder giving P + Q
B. 4 bit subtractor P - Q
C. 4 bit subtractor Q - P
D. 4 bit adder P + Q + R
Answer» C. 4 bit subtractor Q - P
4258.

Periodic recharging of the memory cells at regular intervals of 3 to 8 millisecond is required in a

A. ROM
B. Static RAM
C. Dynamic RAM
D. PLA
Answer» D. PLA
4259.

In order to enable RST 5.5, RST 6.5 and RST 7.5 interrupts, which of the following instructions are needed?

A. El only
B. SIM only
C. El and SIM only
D. None
Answer» D. None
4260.

The frequency of the driving network connected between pins 1 and 2 of a 8085 chip must be

A. equal to the desired clock frequency
B. twice the desired clock frequency
C. four times the desired clock frequency
D. eight times the desired clock frequency
Answer» C. four times the desired clock frequency
4261.

Assertion (A): Divide-64 counter is a Mod-64 counter and divides the input frequency by 64 Reason (R): A Mod 64 counter can be obtained by cascading Mod 16 and Mod 4 counters.

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 true, R is false
D. A is false, R is true
Answer» C. A is true, R is false
4262.

Digital technologies being used now-a-days are

A. DTL and EMOS
B. TTL, ECL, CMOS and RTL
C. TTL, ECL and CMOS
D. TTL, ECL. CMOS and DTL
Answer» C. TTL, ECL and CMOS
4263.

Schmitt trigger can be used as a

A. comparator
B. square-wave generator
C. flip-flop
D. all of these
Answer» E.
4264.

A seven bit code (even parity) 1111101 may have error. The correct code is

A. 1111101
B. 1111111
C. 0101011
D. 1100011
Answer» C. 0101011
4265.

Most of the digital computers do not have floating-point hardware because

A. floating point hardware is costly
B. it is slower than software
C. it is not possible to perform floating point addition by hardware
D. of not specific reason
Answer» B. it is slower than software
4266.

Consider the following statements in connection with CMOS inverter in figure where both the MOSFET are of enhancement type and both have a threshold voltage of 2 Vstatements 1: T1 conducts when vi 2 Vstatements 2: T1 is always in saturation when v0 = 0 VWhich of the following is correct?

A. Only statement 1 is true
B. Only statement 2 is true
C. Both the statement are true
D. Both the statements are false
Answer» B. Only statement 2 is true
4267.

The number of FF required for a divide by 12 circuit is

A. 16
B. 12
C. 8
D. 4
Answer» E.
4268.

The energy to cause thermionic emission is supplied by heating the cathode.

A. True
B. False
Answer» B. False
4269.

Assertion (A): In an n-p-n transistor as the electrons enter the collector region, they are accelerated towards the collector terminal. Reason (R): Emitter base junction in BJT is forward biased.

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» C. A is true but R is false
4270.

Assertion (A): In reverse biased p-n junction, the reverse saturation current is nearly constant if the reverse voltage is less than critical value. Reason (R): The total reverse current is sum of reverse saturation current and surface leakage current.

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» C. A is true but R is false
4271.

If 10 V is the peak voltage across the secondary of the transformer in a half wave rectifier (without any filter circuit), then the maximum voltage on the reverse biased diode will be

A. 20 V
B. 14.14 V
C. 10 V
D. 7.8 V
Answer» D. 7.8 V
4272.

Given a power supply filter circuit, what measurements must be made of determine percentage regulation

A. current through and voltage across the capacitor
B. d.c. load voltage and r.m.s. load voltage
C. current through load and voltage across load resistance
D. number of turns and gauge of secondary winding of transformer
Answer» C. current through load and voltage across load resistance
4273.

Consider the following statements An iron cored choke is a nonlinear device.A carbon resistor kept in a sunlight is a time - invariant and passive device.A dry cell is a time - varying and active device.An air capacitor is a time - invariant and passive device Of these statements

A. 1, 2, 3 and 4 are correct
B. 1, 2 and 3 are correct
C. 1, 2 and 4 are correct
D. 2 and 4 are correct
Answer» B. 1, 2 and 3 are correct
4274.

When the gate terminal of MOSFET is positive, it is said to operate in

A. depletion mode
B. conduction mode
C. enhancement mode
D. none of the above
Answer» D. none of the above
4275.

Assertion (A): In a Schottky diode the reverse recovery time is almost zero. Reason (R): A Schottky diode has aluminium silicon 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
4276.

In energy band diagram of p type semiconductor the acceptor energy level is

A. in valence band
B. in conduction band
C. slightly above valence band
D. slightly below conduction band
Answer» D. slightly below conduction band
4277.

Of the various capacitances associated with a junction transistor the gain bandwidth product is affected to maximum extend by

A. base collector parasitic capacitor
B. base collector space charge layer capacitance
C. base emitter space charge layer capacitance
D. base emitter diffusion capacitance
Answer» E.
4278.

The effect of a finite gain of operational amplifier used in an integrator is that

A. it would not integrator
B. slope of the O/P will varied with time
C. final value of the O/P
D. there will be instability in the cirucuit
Answer» C. final value of the O/P
4279.

The ripple factor from a capacitor filter __________ as the load resistance __________ .

A. decreases, decreases
B. decreases, increases
C. increases, decreases
D. increases, increases
Answer» C. increases, decreases
4280.

The diode and the moving coil milliammeter of figure are assumed to be ideal. The meter reading is

A. 0.1 mA
B. <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/55-417-2.png">
C. <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/55-417-3.png">
D. <img src="/_files/images/electronics-and-communication-engineering/electronic-devices-and-circuits/55-417-4.png">
Answer» E.
4281.

From an n channel JFET for VDS constant and if VGS is made more negative, pinch off would occur at

A. higher value of drain current
B. saturation value of drain current
C. zero drain current
D. gate current equal to drain current
Answer» D. gate current equal to drain current
4282.

The V-I characteristic of a semi-conductor diode is shown in figure. From this figure it can be concluded that

A. The diode is a silicon diode
B. The diode is a germanium diode
C. Break down voltage of the diode is 0.7 V
D. At 1 V rated current will pass through the diode
Answer» B. The diode is a germanium diode
4283.

Electrical contact materials used in switches, brushes and relays must possess

A. high thermal conductivity and high melting point
B. low thermal conductivity and low melting point
C. high thermal conductivity and low melting point
D. low thermal conductivity and high melting point
Answer» B. low thermal conductivity and low melting point
4284.

Measurement of Hall coefficient enables the determination of

A. transportation factor decreases and a increases
B. transportation factor increases and a increases
C. transportation factor increases and a decreases
D. transportation factor decreases and a decreases
Answer» E.
4285.

The process of deliberately adding impurity to a semi-conductor material is called

A. impurification
B. pollution
C. deionisation
D. doping
Answer» E.
4286.

Assertion (A): When a zener diode breakdown, occurs the voltage across it is constant. Reason (R): The upper limit of zener current is determined by power handling capacity.

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» C. A is true but R is false
4287.

In sign magnitude numbers,

A. the leading bit stands for the sign
B. the leading bit is part of the magnitude
C. the leading bit is always 0
D. the leading bit is always 1
Answer» B. the leading bit is part of the magnitude
4288.

A/D parallel converter is also called flash converter.

A. True
B. False
Answer» B. False
4289.

In number system e.g. 6, a decade counter has to recycle to 0 at the sixth count. Which of the connections indicate below will realize this resetting? (a logic 0 at the R inputs resets the counters)

A. <img src="/_files/images/electronics-and-communication-engineering/digital-electronics/50-808-1.png">
B. <img src="/_files/images/electronics-and-communication-engineering/digital-electronics/50-808-2.png">
C. <img src="/_files/images/electronics-and-communication-engineering/digital-electronics/50-808-3.png">
D. None of these
Answer» D. None of these
4290.

In 8085 microprocessor, in order to enable INTR interrupt, which of the following instruction are needed?

A. EI only
B. SIM only
C. El and SIM both
D. None
Answer» B. SIM only
4291.

Logic pulser

A. generates short duration pulses
B. generates long duration pulses
C. generates sinusoidal voltage
D. generates ideal pulses
Answer» B. generates long duration pulses
4292.

The MOS symbol shown indicates that It is depletion typeIt is enhancement typeIt is channelIt is P-channelElectrons flow from s to DHoles flow from D to s The true statements are

A. 1, 3, 6
B. 1, 3, 5
C. 2, 4, 6
D. 2, 3, 5
Answer» E.
4293.

The no. of FF required and the maximum decimal no. of a MOD-12 counter is

A. 12, 12
B. 4, 11
C. 3, 6
D. 4, 10
Answer» C. 3, 6
4294.

In a digital counter the number of flip-flops is

A. always 2
B. always even
C. always odd
D. equal to the number of bits required in the final binary count
Answer» D. equal to the number of bits required in the final binary count
4295.

Assertion (A): Gray code is used in shaft position encoding.Reason (R): In gray code only a single bit change occurs when going from one code to another.

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 true, R is false
D. A is false, R is true
Answer» B. Both A and R are correct but R is not correct explanation of A
4296.

An inductance having XL = 5 &amp;ohm; and a capacitance having XC = 5 &amp;ohm; are connected in parallel across 100 V, 50 Hz supply. The current drawn from source is

A. zero
B. 20 A
C. 40 A
D. 28.28 A
Answer» B. 20 A
4297.

An RLC series circuit is excited by an ac voltage v = 1 sint. If L = 10 H, C = 0.1 F peak value of voltage across R is

A. 0.707 V
B. 1 V
C. 1.44 V
D. indeterminate as value of R is not given
Answer» C. 1.44 V
4298.

The value of the inductance of coil in which a current increases linearly from zero to 0.1A in 0.2 second producing a voltage of 5 volts is __________ .

A. 2.5
B. 5
C. 10
D. 20
Answer» D. 20
4299.

If all other parameters are the same, a capacitor with mica as dielectric has higher capacitance than air capacitor.

A. True
B. False
Answer» B. False
4300.

If V = 100 16 , the (V) is

A. 10 32
B. 10 8
C. 10 16
D. 10 4
Answer» C. 10 16