
In sky-wave propagation, skip distance depends on
(A) Frequency of EM wave transmitted
(B) Critical frequency of layer
(C) Height of layer above the earth’s surface
(D) All of the above
Answer
124.8k+ views
Hint We will see that skip-distance is the distance between the ionosphere and the layer above earth’s surface. It depends on various factors such as frequency, critical frequency and height.
Complete step by step answer
Sky wave: It refers to the signals that travel from earth’s surface towards the ionosphere.
Skip-distance: Minimum distance on the earth’s surface where an EM wave of definite frequency can reach the ionosphere via reflection from the transmitter. It is also known as the dead zone or silent zone. We don’t receive radio transmission.
Formula
${D_{skip}} = 2h\sqrt {\dfrac{{{f^2}}}{{f_c^2}} - 1} $
It depends on various factors -
Frequency (f): As the wave travels from the lower portion, it starts forming an angle. Lower angle starts increasing as frequency starts to increase and returns back from the ionosphere in shorter duration in the beginning. As frequency starts increasing and reaches maximum, it starts showing reflections and rare-fraction by the region of ionosphere.
More the frequency more will skip distance and vice versa.
Critical frequency $\left( {{f_c}} \right)$:
This wave is reflected back and receiver receives on the same site of the transmitter.
Height (h): Distance between maximum point and minimum point.
Since it satisfies all 3 options above, so option D is correct.
Note
We need to keep in mind that there is a critical difference in frequency and frequency. More the critical frequency more is the skip distance whereas more the critical frequency less will be the skip-distance.
Complete step by step answer
Sky wave: It refers to the signals that travel from earth’s surface towards the ionosphere.
Skip-distance: Minimum distance on the earth’s surface where an EM wave of definite frequency can reach the ionosphere via reflection from the transmitter. It is also known as the dead zone or silent zone. We don’t receive radio transmission.
Formula
${D_{skip}} = 2h\sqrt {\dfrac{{{f^2}}}{{f_c^2}} - 1} $
It depends on various factors -
Frequency (f): As the wave travels from the lower portion, it starts forming an angle. Lower angle starts increasing as frequency starts to increase and returns back from the ionosphere in shorter duration in the beginning. As frequency starts increasing and reaches maximum, it starts showing reflections and rare-fraction by the region of ionosphere.
More the frequency more will skip distance and vice versa.
Critical frequency $\left( {{f_c}} \right)$:
This wave is reflected back and receiver receives on the same site of the transmitter.
Height (h): Distance between maximum point and minimum point.
Since it satisfies all 3 options above, so option D is correct.
Note
We need to keep in mind that there is a critical difference in frequency and frequency. More the critical frequency more is the skip distance whereas more the critical frequency less will be the skip-distance.
Recently Updated Pages
The ratio of the diameters of two metallic rods of class 11 physics JEE_Main

What is the difference between Conduction and conv class 11 physics JEE_Main

Mark the correct statements about the friction between class 11 physics JEE_Main

Find the acceleration of the wedge towards the right class 11 physics JEE_Main

A standing wave is formed by the superposition of two class 11 physics JEE_Main

Derive an expression for work done by the gas in an class 11 physics JEE_Main

Trending doubts
JEE Main 2025 Session 2: Application Form (Out), Exam Dates (Released), Eligibility & More

Class 11 JEE Main Physics Mock Test 2025

JEE Main Exam Marking Scheme: Detailed Breakdown of Marks and Negative Marking

JEE Main 2023 January 24 Shift 2 Question Paper with Answer Keys & Solutions

Learn About Angle Of Deviation In Prism: JEE Main Physics 2025

JEE Main 2025: Conversion of Galvanometer Into Ammeter And Voltmeter in Physics

Other Pages
JEE Advanced Marks vs Ranks 2025: Understanding Category-wise Qualifying Marks and Previous Year Cut-offs

NCERT Solutions for Class 11 Physics Chapter 1 Units and Measurements

NCERT Solutions for Class 11 Physics Chapter 9 Mechanical Properties of Fluids

Units and Measurements Class 11 Notes: CBSE Physics Chapter 1

NCERT Solutions for Class 11 Physics Chapter 2 Motion In A Straight Line

NCERT Solutions for Class 11 Physics Chapter 7 Gravitation
