1. In parametric amplifiers used in microwave communication systems, the gain is mainly restricted by ?

pump frequency

pump bandwidth

ambient temperature

pump energy

Answer: pump frequency

Explanation:


2. A screw projection in a waveguide is ?

capacitive discontinuity

an inductive discontinuity

either (a) or (b)

resistive discontinuity

Answer: resistive discontinuity

Explanation:


3. A matched load is a ?

variable attenuator

fixed attenuator

rotary attenuator

phase shifter

Answer: fixed attenuator

Explanation:


4. To couple a coaxial line to a parallel wire, it is best to use a ?

Slotted line

Directional coupler

Balun

Quarter wave transformer

Answer: Balun

Explanation:


5. Baratters and bolometers are used for measurement of ?

VSWR

microwave power

frequency

transmission losses

Answer: microwave power

Explanation:


6. A cylindrical cavity resonator has diameter of 24 mm and length 20 mm. The dominant mode and the lowest frequency band are operated as ?

TM011 and Ku-band

TM010 and X-band

TM and C-band

TE and X-band

Answer: TM010 and X-band

Explanation:


7. The phase velocity of an electromagnetic wave propagating in a hollow metallic rectangular waveguide in the TE mode is ?

equal to the velocity of light in free space

less than the velocity of light in free space

greater than the velocity of light in free space

equal to its group velocity

Answer: greater than the velocity of light in free space

Explanation:


8. Which of the following introduces mode partition noise ?

Fibre transmission line

Coaxial line

Waveguide

Both coaxial line and waveguide

Answer: Coaxial line

Explanation:


9. When electromagnetic waves are propagated in a waveguide ?

they are reflected from the walls but do not travel along the walls

they travel along the walls of the waveguide

they travel through the dielectric without touching the walls

None of these

Answer: they are reflected from the walls but do not travel along the walls

Explanation:


10. Pure TEM mode is the propagation mode in ?

strip line

microstrip line

coplanar waveguide

slot line

Answer: coplanar waveguide

Explanation: