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.

3001.

Which of the following can be operated with positive as well as negative gate voltage?

A. JFET
B. Both JFET and MOSFET
C. MOSFET
D. Neither JFET nor MOSFET
Answer» D. Neither JFET nor MOSFET
3002.

The reverse breakdown voltage of a diode depends on the extent of doping.

A. True
B. False
Answer» B. False
3003.

The turn off time of a bipolar transistor is about

A. 0.5 ns
B. 10 ns
C. 70 ns
D. 150 ns
Answer» D. 150 ns
3004.

Hystresis loss least depends on

A. frequency
B. magnetic field intensity
C. volume of the material
D. grain orientation of material
Answer» E.
3005.

In a bipolar transistor, emitter efficiency is about

A. 0.99
B. 0.9
C. 0.8
D. 0.7
Answer» B. 0.9
3006.

For signal diodes the PIV rating is usually in the range

A. 1 V to 10V
B. 10 V to 30V
C. 30 V to 150V
D. 150 V to 400V
Answer» D. 150 V to 400V
3007.

The potential of suppressor grid (with respect to cathode) is usually

A. zero
B. negative
C. positive
D. zero or positive
Answer» B. negative
3008.

If the atomic number of germanium is 32, the number of electrons in the outer most shell will be

A. 2
B. 3
C. 4
D. 6
Answer» D. 6
3009.

Dielectric loss due to polarisation occurs in

A. bipolar dielectrics
B. non-metallic dielectrics
C. liquid dielectrics
D. all of the above
Answer» B. non-metallic dielectrics
3010.

A metal loses electrons at room temperature.

A. True
B. False
Answer» C.
3011.

Consider the following statement associated with bipolar junction transistor and JFET The former has higher input impedance than the laterThe former has higher frequency stability than the laterThe later has lower noise figure than the formerThe later has higher power rating than the former. Of these statements

A. 1 and 2 are correct
B. 2 and 3 are correct
C. 3 and 4 are correct
D. 1 and 4 are correct
Answer» C. 3 and 4 are correct
3012.

If the energy gap of a semiconductor is 1.1 eV, then it would be

A. opaque to visible light
B. transparent to visible light
C. transparent to ultraviolet radiation
D. transparent to infrared radiation
Answer» B. transparent to visible light
3013.

The voltage at which Avalanche occurs is known as

A. cut in voltage
B. barrier voltage
C. breakdown voltage
D. depletion voltage
Answer» D. depletion voltage
3014.

The resistivity of a semiconductor

A. increases as the temperature increases
B. decreases as the temperature increases
C. remains constant even when temperature varies
D. none of the above
Answer» C. remains constant even when temperature varies
3015.

In intrinsic semiconductor the increase in conductivity per degree increase in temperature is about

A. 2%
B. 6%
C. 15%
D. 25%
Answer» C. 15%
3016.

The ripple factor for a bridge rectifier is

A. 0.406
B. 1.21
C. 1.11
D. 2.22
Answer» C. 1.11
3017.

In the BJT amplifier shown in the figure is the transistor is biased in the forward active region. Putting a capacitor across RE will

A. decrease the voltage gain and decrease the I/P impedance
B. increase the voltage gain and decrease the I/P Impedance
C. decrease the voltage gain and Increase the I/P impedance
D. none of the above
Answer» C. decrease the voltage gain and Increase the I/P impedance
3018.

Consider the following statements.The functions of an oxide layer in an IC device is to mask against diffusion or ion implantinsulate the surface electricallyincrease the melting point of siliconproduce a chemically stable protective layer of these statements.

A. 1, 2, 3
B. 1, 3, 4
C. 2, 3, 4
D. 1, 2, 4
Answer» E.
3019.

In a centre tap full wave rectifier, 50 V is the peak voltage between the centre tap and one of the ends of the secondary. The maximum voltage across the reverse biased diode will be

A. 100 V
B. 72 V
C. 50 V
D. 38 V
Answer» B. 72 V
3020.

Assertion (A): A BJT can be used as a switch. Reason (R): In forward active mode emitter base junction is forward biased and base collector junction is reverse 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
3021.

The forbidden energy gap for germanium is

A. 0.12 eV
B. 0.32 eV
C. 0.72 eV
D. 0.92 eV
Answer» D. 0.92 eV
3022.

The concentration of minority carriers in an extrinsic semiconductor under equilibrium is

A. directly proportional to the doping concentration
B. inversely proportional to doping concentration
C. directly proportional to intrinsic concentration
D. inversely proportional to the intrinsic concentration
Answer» C. directly proportional to intrinsic concentration
3023.

The mean life time of the minority carriers is in the range of a few

A. seconds
B. milli seconds
C. micro seconds
D. nano seconds
Answer» E.
3024.

Choose the correct match for input resistance of various amplifier configurations shown below configuration.CB : Common Base LO : LowCC : Common Collector MO : moderateCE : Common EmitterHI: High

A. CB-LO, CC-MO, CE-HI
B. CB-LO, CC-HI, CE-MO
C. CB-MO, CC-HI, CE-LO
D. CB-HI, CC-LO, CE-MO
Answer» C. CB-MO, CC-HI, CE-LO
3025.

A long specimen of P type semiconductor material

A. is + vely charged
B. is electrically neutral
C. has an electric field directed along its length
D. acts as a dipole
Answer» C. has an electric field directed along its length
3026.

An inductor filter has a ripple that __________ with load resistance and consequently is used only with relatively __________ load currents.

A. decreases, low
B. decreases, high
C. increases, low
D. increases, high
Answer» E.
3027.

Electric breakdown strength of a material depends on its

A. composition
B. moisture content
C. thickness
D. all of the above
Answer» E.
3028.

The atomic weight of an atom is determined by

A. the number of protons
B. the number of neutrons
C. the number of protons and neutrons
D. the number of electrons and protons
Answer» D. the number of electrons and protons
3029.

The minimum charge carried by an ion is

A. zero
B. equal to the change of an electron
C. equal to the change of a pair of electrons
D. equal to the change of electrons left in the atom
Answer» C. equal to the change of a pair of electrons
3030.

Which statement is false as regards holes

A. Holes exist in conductors as well as semiconductors
B. Holes constitute positive charges
C. Holes exist only in semiconductors
D. Holes and electrons recombine
Answer» B. Holes constitute positive charges
3031.

Photo electric emission can occur only if

A. wave length of incident radiation is equal to threshold value
B. wave length of incident radiation is less than threshold value
C. frequency of incident radiation is less than threshold frequency
D. none of the above
Answer» C. frequency of incident radiation is less than threshold frequency
3032.

The reverse saturation current of a diode does not depend on temperature.

A. True
B. False
Answer» C.
3033.

The drain characteristics of JFET in operating region, are

A. inclined upwards
B. almost flat
C. inclined downwards
D. inclined upwards or downwards
Answer» C. inclined downwards
3034.

The value of a in a transistor

A. is always equal to 1
B. is less than 1 but more than 0.9
C. is about 0.4
D. is about 0.1
Answer» C. is about 0.4
3035.

In a piezoelectric crystal, application of a mechanical stress would produce

A. plastic deformation of the crystal
B. magnetic Dipoles in the crystal
C. electric polarization in the crystal
D. shift in the Fermi level
Answer» D. shift in the Fermi level
3036.

As temperature increases

A. the forbidden energy gap in silicon and germanium increase
B. the forbidden energy gap in silicon and germanium decrease
C. the forbidden energy gap in silicon decreases while that in germanium decreases
D. the forbidden energy gap in silicon increases while that in germanium decreases
Answer» C. the forbidden energy gap in silicon decreases while that in germanium decreases
3037.

When a reverse bias is applied to a p-n junction, the width of depletion layer.

A. decreases
B. increases
C. remains the same
D. may increase or decrease
Answer» C. remains the same
3038.

For BJT transistor. The maximum power dissipation is specified as 350 mW if ambient temperature is 25 C. If ambient temperature is 60 C the maximum power dissipation should be limited to about

A. 100 mW
B. 250 mW
C. 450 mW
D. 600 mW
Answer» C. 450 mW
3039.

Which of the following devices has a silicon dioxide layer?

A. NPN transistor
B. Tunnel diode
C. JFET
D. MOSFET
Answer» E.
3040.

In a bipolar junction transistor the base region is made very thin so that

A. recombination in base region is minimum
B. electric field gradient in base is high
C. base can be easily fabricated
D. base can be easily biased
Answer» B. electric field gradient in base is high
3041.

Which of the following has highest conductivity?

A. Silver
B. Aluminium
C. Tungsten
D. Platinum
Answer» B. Aluminium
3042.

The concentration of minority carriers in a semiconductor depends mainly on

A. the extent of doping
B. temperature
C. the applied bias
D. none of the above
Answer» C. the applied bias
3043.

Compared to bipolar junction transistor, a JFET has

A. lower input impedance
B. high input impedance and high voltage gain
C. higher voltage gain
D. high input impedance and low voltage gain
Answer» E.
3044.

A diode is operating in forward region and the forward voltage and current are v = 3 + 0.3 sin t (volts) and i = 5 + 0.2 sin t (mA). The average power dissipated is

A. 15 mW
B. about 15 mW
C. 1.5 mW
D. about 1.5 mW
Answer» C. 1.5 mW
3045.

The amount of photoelectric emission current depends on the frequency of incident light.

A. True
B. False
Answer» C.
3046.

When a p-n junction is forward biased

A. the width of depletion layer increases
B. the width of depletion layer decreases
C. the majority carriers move away from the junction
D. the current is very small
Answer» C. the majority carriers move away from the junction
3047.

The carriers of n channel JFET are

A. free electrons and holes
B. holes
C. free electrons or holes
D. free electrons
Answer» E.
3048.

The depletion layer around p-n junction in JFET consists of

A. hole
B. electron
C. immobile charges
D. none of the above
Answer» D. none of the above
3049.

Junction temperature is always the same as room temperature.

A. True
B. False
Answer» C.
3050.

If the reverse voltage across a p-n junction is increased three times, the junction capacitance

A. will decrease
B. will increase
C. will decrease by an approximate factor of about 2
D. will increase by an approximate factor of about 2
Answer» D. will increase by an approximate factor of about 2