1. In order to couple two generators to a waveguide system without coupling them to each other one, one could not use a ?

Magic Tee

hybrid ring

E-plane Tee

rat-race

Answer: E-plane Tee

Explanation:


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

Reflex klystron

Travelling wave tube

Magnetron

Gunn diode

Answer: Travelling wave tube

Explanation:


3. The TWT amplifier is sometimes preferred to the multicavity klystron amplifier because the former ?

is more efficient

has a higher number of modes

has a greater BW

produces high output power

Answer: has a greater BW

Explanation:


4. In travelling wave tube microwave amplifiers, the velocity modulation and bunching of electrons are achieved by the electromagnetic wave supported in the slow wave structure. Which one of the following field components is responsible for the above ?

The electric field component transverse to the electron beam propagation

The magnetic field component in the direction of the electron beam propagation

The electric field component in the direction of the electron beam propagation

The magnetic field component transverse to the electron beam propagation

Answer: The electric field component in the direction of the electron beam propagation

Explanation:


5. Microwave source used for a microwave oven is ?

reflex klystron

BWO

magnetron

IMPATT diode

Answer: magnetron

Explanation:


6. Cylindrical cavity resonators are not used with klystron because they have ?

a shape whose resonant frequency is too difficult

a Q that is too low

too heavy losses

harmonically related resonant frequencies

Answer: a shape whose resonant frequency is too difficult

Explanation:


7. To avoid difficulties with strapping at high frequencies, what type of cavity structure is used in the magnetron ?

Hole and slot

Rising sun

Slot

Vane

Answer: Rising sun

Explanation:


8. In a VSWR measurement, a square law detector is used to detect the signal level. The voltmeter reads maximum and minimum as 64 mV and 16 mV respectively. The VSWR of the system will be ?

2

4

8

16

Answer: 4

Explanation:


9. The 'Double minimum or the "Width of minimum power" method is used in microwave measurements for the measurement of ?

high VSWR

frequency distortion

velocity modulation

low VSWR

Answer: high VSWR

Explanation:


10. "Double-the-minimum" method is relevant to the measurement of ?

high attenuation coefficient

high VSWR

low attenuation coefficient

low VSWR

Answer: high VSWR

Explanation: