Explore topic-wise MCQs in Antennas.

This section includes 11 Mcqs, each offering curated multiple-choice questions to sharpen your Antennas knowledge and support exam preparation. Choose a topic below to get started.

1.

Find the MUF for the wave operating at a critical frequency 6MHz and having the skip distance d as 25km and virtual height of 100km in the ionosphere layer.

A. 6.05MHz
B. 1.25MHz
C. 1.025MHz
D. 3.25MHz
Answer» B. 1.25MHz
2.

What is the refractive index of the region operating at 16MHz frequency with the electron density 49 1010/cm3?

A. 0.518
B. 0.919
C. 0.155
D. 0.845
Answer» C. 0.155
3.

Suppose a ray is incident normally in the ionosphere region with electron density 25 1010/cm3, then the Maximum usable frequency is _____

A. 5GHz
B. 45MHz
C. 4.5MHz
D. 125GHz
Answer» D. 125GHz
4.

Which of the following is true when a ray is incident normally in an Ionosphere region?

A. MUF is equal to critical frequency
B. MUF is greater than critical frequency
C. MUF is less than critical frequency
D. MUF is zero
Answer» B. MUF is greater than critical frequency
5.

What is the value of maximum usable frequency when the incident angle is 60 and the critical frequency is 4.5MHz?

A. 4.5MHz
B. 2.25MHz
C. 9MHz
D. 18MHz
Answer» D. 18MHz
6.

Skip distance is the _____

A. Minimum distance at which wave returns back at the lowest possible frequency
B. Maximum distance at which wave returns back at the critical frequency
C. Minimum distance at which wave returns back at the critical angle
D. Maximum distance at which wave returns back at the lowest possible frequency
Answer» D. Maximum distance at which wave returns back at the lowest possible frequency
7.

Relation between MUF and critical frequency is ______

A. f<sub>c</sub> = f<sub>MUF</sub> sec <sub>i</sub>
B. f<sub>MUF</sub> = f<sub>c</sub> sec<sup>2</sup> <sub>i</sub>
C. f<sub>c</sub> = f<sub>MUF</sub> sin <sub>i</sub>
D. f<sub>MUF</sub> = f<sub>c</sub> sec <sub>i</sub>
Answer» E.
8.

Suppose a ray is incident normally in the ionosphere region with electron density 36 1010/cm3, then the critical frequency is _____

A. 5GHz
B. 54MHz
C. 5.4MHz
D. 324GHz
Answer» D. 324GHz
9.

The frequency below which the entire power gets absorbed is called as ____

A. MUF
B. LUF
C. Critical frequency
D. Optimum frequency
Answer» C. Critical frequency
10.

If wave exceeds the MUF then it is not reflected back.

A. True
B. False
Answer» B. False
11.

The maximum possible frequency for which the wave is reflected back for a given distance of propagation in the ionosphere layer is called as_______

A. Maximum usable frequency
B. Critical frequency
C. Resonance frequency
D. Dominating frequency
Answer» B. Critical frequency