Explore topic-wise MCQs in Electrical Engineering.

This section includes 247 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

Indicate which one of the following modes do not exist in a rectangularresonantcavity

A. te110
B. tm110
C. te011
D. mt111
Answer» B. tm110
52.

Calculate the transmission coefficient, when the incident and transmitted amplitudes are10 and 7 respectively.

A. 17
B. 3
C. 10/7
D. 0.7
Answer» E.
53.

Find the characteristic impedance of a quarter wave with input and load impedances given by50 and 25 respectively.

A. 50
B. 25
C. 75
D. 35.35
Answer» E.
54.

Propagation constant γ is given by:

A. α+jβ
B. α-jβ
C. α/jβ
D. α.jβ
Answer» B. α-jβ
55.

Indicate the false statement. The SWR on a transmission line is infinity; the line isterminated in

A. a short circuit
B. an open circuit
C. a complex impedance
D. pure reactance
Answer» D. pure reactance
56.

If a transmission line of a characteristics impedance 50 Ω is terminated with a loadimpedance of 100 Ω, then the reflection co efficient is:

A. 0.3334
B. 0.6667
C. 1.6
D. 1.333
Answer» B. 0.6667
57.

Maxwell’s equation for electromagnetic waves in a waveguide is:

A. ∇×e = -jωµ(vector h)
B. ∇×e =-jωμ(vector e)
C. ∇×h=-jωμ(vector h)
D. ∇×h=jωμ(vector h)
Answer» B. ∇×e =-jωμ(vector e)
58.

Expression for the characteristic impedance of a transmission line(λ/4) used for impedance matching is:

A. z1=√(zₒr)l
B. z1=√(zₒ/r)l
C. z1=√(zₒ+r)l
D. none of the mentioned
Answer» B. z1=√(zₒ/r)l
59.

If a device is passive and contains no anisotropic elements, then the deviceis_______ network.

A. reciprocal
B. non reciprocal
C. lossless
D. lossy
Answer» B. non reciprocal
60.

ency of 30GHz is (free space impedance 0 =377 Ω)

A. 308 Ω
B. 400 Ω
C. 355 Ω
D. 461 Ω
Answer» C. 355 Ω
61.

When the electric field applied to GaAs specimen is less than the threshold electricfield, the current in the material:

A. increases linearly
B. decreases linearly
C. increases exponentially
D. decreases exponentially
Answer» B. decreases linearly
62.

If a transmission line of characteristic impedance 50 Ω is terminated with a loadimpedance of 150 Ω , then VSWR is:

A. 0.75
B. 0.5
C. 2
D. none of the mentioned
Answer» B. 0.5
63.

The junction resistance and capacitance of the intrinsic region in a PIN diode areconnected______ in the equivalent circuit of PIN diode.

A. series
B. parallel
C. connected across package capacitance
D. none of the mentioned
Answer» C. connected across package capacitance
64.

Power dividers and couplers are ______ microwave components used for powerdivision or power combining.

A. passive
B. active
C. linear
D. non linear
Answer» B. active
65.

The radar in which both transmission and reception is done using the sameantenna are called:

A. monostatic
B. bistatic
C. dipole radar
D. monopole radar
Answer» B. bistatic
66.

_________ and __________ contribute to the impedance of a transmission line in thelumped element representation.

A. resistor, inductor
B. resistor, capacitor
C. capacitor, inductor
D. transistor, capacitor
Answer» B. resistor, capacitor
67.

Processing in MMICs is done by __________

A. ion implantation
B. net list generation
C. floor planning
D. none of the mentioned
Answer» B. net list generation
68.

For the capacitors used in MMICs, the insulating dielectric films used are:

A. air
B. sio
C. titanium
D. gaas
Answer» C. titanium
69.

The substrate of an MMIC must be a _____________ to accommodate the fabrication of all the type of devices.

A. semiconductor
B. insulator
C. partial conductors
D. metals operable at high frequencies
Answer» B. insulator
70.

The maximum theoretical output circuit efficiency of a double resonator klystron amplifier is

A. 25%
B. 50%
C. 58%
D. 85%
Answer» D. 85%
71.

Which of the following is not possible in a circular wave guide ?

A. te10
B. te01
C. te11
D. te12
Answer» B. te01
72.

A cavity resonator can be represented by

A. an lc circuit
B. an lcr circuit
C. a lossy inductor
D. a lossy capacitor
Answer» B. an lcr circuit
73.

Ionospheric preparation is not possible for microwaves because

A. microwaves will be fully absorbed by the ionospheric layers
B. there will be an abrupt scattering in all directions
C. microwave will penetrate through the ionospheric layers
D. there will be dispersion of microwave energy
Answer» D. there will be dispersion of microwave energy
74.

When the electric field applied to GaAs specimen is less than the threshold electric field, the current in the material:

A. increases linearly
B. decreases linearly
C. increases exponentially
D. decreases exponentially
Answer» B. decreases linearly
75.

Which of the following can be used for amplification of microwave energy?

A. magnetron
B. reflex klystron
C. traveling wave tube
D. gunn diode
Answer» D. gunn diode
76.

Klystrons operates on the principal of

A. amplitude modulation
B. frequency modulation
C. pulse modulation
D. velocity modulation
Answer» E.
77.

________ is a single cavity klystron tube that operates as on oscillator by using a reflector electrode after the cavity.

A. backward wave oscillator
B. reflex klystron
C. travelling wave tube
D. magnetrons
Answer» C. travelling wave tube
78.

When a reverse bias voltage exceeding the breakdown voltage is applied to an IMPATT diode, it results in:

A. break down of depletion region
B. avalanche multiplication
C. high reverse saturation current
D. none of the mentioned
Answer» C. high reverse saturation current
79.

The width of depletion region of a varactor diode ________with increase in reverse bias voltage.

A. increases
B. decreases
C. remains constant
D. none of the mentioned
Answer» B. decreases
80.

The junction resistance and capacitance of the intrinsic region in a PIN diode are connected______ in the equivalent circuit of PIN diode.

A. series
B. parallel
C. connected across package capacitance
D. none of the mentioned
Answer» C. connected across package capacitance
81.

If a microwave network is lossless, then S matrix of the microwave network is:

A. zero matrix
B. symmetric
C. identity matrix
D. unitary
Answer» E.
82.

If a device is passive and contains no anisotropic elements, then the device is_______ network.

A. reciprocal
B. non reciprocal
C. lossless
D. lossy
Answer» B. non reciprocal
83.

T- junction is an example for:

A. 2 port network
B. 3 port network
C. 4 port network
D. none of the mentioned
Answer» C. 4 port network
84.

Power dividers and couplers are ______ microwave components used for power division or power combining.

A. passive
B. active
C. linear
D. non linear
Answer» B. active
85.

The device commonly used in microwave ovens is the:

A. twt
B. klystron
C. magnetron
D. yig
Answer» D. yig
86.

A “circulator” is a device that:

A. rotates signal polarity in a waveguide
B. allows a signal to pass in one direction only
C. separates signals among various ports
D. prevents microwaves from being “trapped” in a waveguide
Answer» D. prevents microwaves from being “trapped” in a waveguide
87.

Directional coupler for waveguide are characterized by

A. insertion loss
B. coupling specification
C. directivity
D. all of the above
Answer» E.
88.

Ferrite isolators are ____ port microwave devices.

A. two
B. three
C. four
D. none of the mentioned
Answer» B. three
89.

S parameters are expressed as a ratio of:

A. voltage and current
B. impedance at different ports
C. indecent and the reflected voltage waves
D. none of the mentioned
Answer» D. none of the mentioned
90.

TEâ‚’â‚’ mode for a rectangular waveguide:

A. exists
B. exists but defined only under special cases
C. does not exist
D. cannot be determined
Answer» D. cannot be determined
91.

In TM mode, if the direction of wave propagation is in ‘z’ direction, then:

A. hz=0
B. ez=0
C. ey=0
D. hy=0
Answer» B. ez=0
92.

The modes of wave propagation that a rectangular waveguide can support are:

A. tem, te, modes
B. tem,tm, te modes
C. tem, tm modes
D. te,tm modes
Answer» E.
93.

Maxwell’s equation for electromagnetic waves in a waveguide is:

A. ∇×e = -jωµ(vector h)
B. ∇×e =-jωμ(vector e)
C. ∇×h=-jωμ(vector h)
D. ∇×h=jωμ(vector h)
Answer» B. ∇×e =-jωμ(vector e)
94.

For co-axial lines and waveguides, ________ is more preferred.

A. open circuited stub
B. short circuited stub
C. slotted section
D. co-axial lines cannot be impedance matched
Answer» C. slotted section
95.

In shunt stub matching, the key parameter used for matching is:

A. admittance of the line at a point
B. admittance of the load
C. impedance of the stub
D. impedance of the load
Answer» B. admittance of the load
96.

Shunt stubs are preferred for:

A. strip and microstrip lines
B. coplanar waveguides
C. circular waveguide
D. circulators
Answer» B. coplanar waveguides
97.

The major advantage of single stub tuning over other impedance matching techniques is:

A. lumped elements are avoided
B. it can be fabricated as a part of transmission line media
C. it involves two adjustable parameters
D. all of the mentioned
Answer» E.
98.

Characteristic impedance of a transmission line is:

A. impedance z of a transmission line
B. impedance which is a constant at any point on the transmission line
C. reciprocal of admittance of a transmission line
D. none of the mentioned
Answer» C. reciprocal of admittance of a transmission line
99.

Transmission line is a _________ parameter network.

A. lumped
B. distributed
C. active
D. none of the mentioned
Answer» C. active
100.

_________ and __________ contribute to the impedance of a transmission line in the lumped element representation.

A. resistor, inductor
B. resistor, capacitor
C. capacitor, inductor
D. transistor, capacitor
Answer» B. resistor, capacitor