Which layer of the earth’s atmosphere reflects back the radio waves to the earth’s surface?
Long distance propagation of radio waves depends on an invisible layer of charged particles, which envelops the Earth. This layer of charged particles known as the ionosphere has been in existence for millions of years. For those, who pioneered the long-distance radio communication during the early part of the twentieth century, the ionosphere came as a boon.
According to the writer, the ancient Indian iron and steel industry was famous, because:
...Which of the following word is similar in meaning to imperial as used in the passage?
Which of the following statements is /are true based on the information and facts mentioned in this passage?
(A) While taking a decision on th...
Which of the following options proves the origination of oil in the sea?
Freedom of speech and expression is a part of which article of the constitution?
Which of the following words seems the most opposite in meaning to the word 'mend' s used in the passage?
What does the word “imprisoned” mean in context of the passage?
What is true about the device being made by the engineering researchers at California NanoSystems Institute?
What is the main objective of the Paris Agreement, as discussed in the passage?
What has increased because of new opportunities presented by Africa’s emerging markets?