1. Reflection occurs because of the following cases

The cutoff wave length of the waveguide in microwave bench is ________

Both axial magnetic field and radial electric fields are used in the following vacuum tube

1. A direction coupler is

Which device is based on Faraday rotation?

How much phase shift does an isolator produce in forward direction?

The cut-off frequency of a waveguide depends on

One of the important characteristic of microwave frequencies is

The dominant TE mode in rectangular waveguides is

In rectangular waveguide, for dominant mode, the cut-off wave length is

An E-plane tee is

An H-plane tee is

Co-planar arm ports in 3-port junctions can be

1. The time taken by the electron to travel into the repeller space and back to the gap in a reflex klystron is referred to as

The PIN diode is must suited for......applications

During forward bias, the PIN diode acts as _______

A phototransistor produces more current than a photodiode because

Compared to a photo-diode, which of the listed advantages and disadvantages would be expected of a photo-transistor

When a photon of sufficient energy strikes the diode, it excites an electron, thereby creating a free electron. What is this phenomenon called?

Phototransistors based on hetero-junction using _________ material are known as waveguide phototransistors.

LEDs made with GaAs emit light in

What should be the bandgap of semiconductor to be used as an LED

For a GaAs LED, the coupling efficiency is 0.05. Compute the optical loss in decibels.

In an optical fiber, the concept of Numerical aperture is applicable in describing the ability of __________

choose the correct block diagram of optical fiber communication system

What is the range of fiber optics communication?

During Total Internal Reflection light moves from

The unit of Numerical aperature is

In the fiber optic link, power transfer from one fiber to another and from fiber to detector must take place with _________coupling efficiency.

A step-index fibre has a numerical aperture of 0.26, a core refractive index of 1.5 and a core diameter of 100micrometer. Calculate the acceptance angle.

The numerical aperture of a material with acceptance angle of 60 degree in water will be

The V number of a fiber is 4. then the fiber is

The minimum angle of incidence ( $\theta$ 1) at which the ray strikes the interface of the two medium and causes an angle of refraction ( $\theta$ 2) equal to 90 $\degree$  is known as

The maximum angle with which a ray of light can enter through the fiber and still be totally internally reflected is known as

Determine the NA of fiber with  core refractive index of 1.5 and a cladding refractive index of 1.47.

Determine the NA of fiber with the acceptance angle 17.36 $\degree$ 

 $\sqrt{n_1^2-n_2^2}$  is

An E plane Tee is also called a

In a shunt-tee, the axis of the side-arm is in

Which one of the following is also called 'rat race'?

The number of ports in Directional Coupler are

The conditions for all ports to be perfectly matched

In a Reflex klystron if the repeller voltage is reduced for a constant value of beam voltage, then the output power of successive modes will be;

Klystron operates on the principle of-

The microwave sources used for a micrwave oven is

The modes in a reflex Klystron

A reflex Klystron fuctions as

A measure of the mismatched between line and load impedance is called as