Explore topic-wise MCQs in Engineering.

The width of a radio beam from a 1 m diameter parabolic antenna at 10 GHz is about

The diagram to show distance time history of electrons in klystron amplifier is called

Impedance level of Impatt diodes is generally lower than that of Gunn diodes

A quarter wave line open circuited at far end behaves as

Which of the following is taken as reference antenna for directive gain?

Push pull amplifier is

When the channel is noisy, producing a conditional probability of error p = 0.5; the channel capacity and entropy function would be, respectively,

In CCIR-B system, the time between start of one H syn. pulse and next is

Counterpoise is used in coils having

The fabrication of microstrip line is done by

The condition of minimum distortion in a transmission line is

In a travelling wave tube distributed interaction between an electron beam and a travelling wave takes place

A line has Z₀ = 300 0 . If Z_L = 150 0 , reflection coefficient is

In a microstrip transmission the signal can be easily redirected by changing the centre strip.

The frequency of oscillation in a backward wave oscillator can be changed by

A line has a phase constant of 29.8 rad/m. At 1000 MHz the wavelength is

Assertion (A): A backward wave oscillator has an internal positive feedback.

Reason (R): A positive feedback is necessary for sustained oscillations.

In sound recording the degree of pre-emphasis is about 6 dB/ octave.

Space wave may be a direct wave or wave reflected from earth.

Radio broadcasts are generally

If the frequency of a wave 20 Hz, the time period is

Which of the following lines is non-radiating?

Assertion (A): The impedance of a matched load is equal to characteristic impedance of line.

Reason (R): A matched termination absorbs all the power incident on it.

Skin effect is more pronounced at high frequencies.

Assertion (A): The phenomenon of differential mobility is called transferred electron effect.

Reason (R): GaAs exhibits transferred electron effect.

Loss angle of a good quality cable is about

In a three cavity klystron amplifier, the oscillations are excited in

Which of the following devices uses a helix?

In a directional coupler

As the frequency is increased, the charging MVAR in a cable

Assertion (A): A coaxial line is a non-radiating line.

Reason (R): In a coaxial line the electric and magnetic fields are confined to the region between the concentric conductors.

Reflex klystron oscillator is essentially a low power device

A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100 km, the characteristic impedance is

A matched generator (Z_g = Z₀) with 1 available. If all ports are matched, the power delivered at ports 1, 2, 3 respectively are

The action of backward wave oscillator is similar to that of

In the given figure the reflection coefficient at source end is

Assertion (A): Artificial transmission lines are frequently used in laboratories.

Reason (R): An artificial transmission line can be used to represent an actual line and can also be used as a delay circuit, as attenuator, as filter network etc.

A resistive microwave load with Z_L = 150 is connected to 50 coaxial line. SWR is

Which of the following devices uses a slow wave structure?

In a turnstile antenna two-half wave resonant wire radiators are placed at 90 to each other in the same plane and are excited

In the given figure reflection coefficient at load is

In a backward wave oscillator the wave travelling along the line winds itself back and forth

A line is excited by a 100 V dc source. If reflection coefficients at both ends are 1 each then

A waveguide section in a microwave circuit acts as