Radio Waves: The Invisible Messengers: Reading Answers & Explanations
IELTS Reading practice test · 13 questionsAcademiceasy
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About this passage
The passage opens: “At this very moment the air around us is filled with invisible signals carrying music, voices and streams of data from one place to another. We cannot see, hear or feel them directly, yet without them there would be no radio, no television as we knew it, no mobile telephones and no wireless internet.”
- Passage length: about 686 words
- Questions: 13
- Question types: True / False / Not Given, Multiple Choice, Note Completion
“Radio Waves: The Invisible Messengers” is an original IELTS-style practice passage written by IELTS-Bank. It is not taken from an official IELTS or Cambridge test, so these answers only apply to our version.
Answer key at a glance
Radio Waves: The Invisible Messengers answers with explanations
Questions 1–6: True / False / Not Given
Do the following statements agree with the information given in the passage? Write TRUE if the statement agrees, FALSE if it contradicts, or NOT GIVEN if there is no information.
- 1
Radio waves belong to the same family as visible light.
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Answer: TRUE
Why: This sentence confirms the statement, so the answer is TRUE.
Evidence · Paragraph 2 “Radio waves belong to the same family as visible light. Both are forms of what scientists call electromagnetic waves”
- 2
Radio waves travel more slowly than visible light.
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Answer: FALSE
Why: This sentence directly contradicts the statement, so the answer is FALSE.
Evidence · Paragraph 2 “…radio waves travel at exactly the same speed as light”
- 3
Radio waves can pass through the walls of a building.
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Answer: TRUE
Why: This sentence confirms the statement, so the answer is TRUE.
Evidence · Paragraph 2 “…unlike light, they can pass straight through the walls of a building.”
- 4
The range of frequencies available for radio use is unlimited.
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Answer: FALSE
Why: This sentence directly contradicts the statement, so the answer is FALSE.
Evidence · Paragraph 3 “…it is a limited resource that has to be shared out carefully by international agreement.”
- 5
Radio was first used to send messages to ships at sea.
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Answer: NOT GIVEN
Why: The statement claims radio was first used to send messages to ships at sea, but the passage never confirms or denies this, focusing instead on how radio waves work and their role in modern communication.
Closest related text · Paragraph 4 “To send a broadcast, a station must first find a way of carrying sound upon a radio wave.”
- 6
Radar is one use of radio waves besides broadcasting.
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Answer: TRUE
Why: This sentence confirms the statement, so the answer is TRUE.
Evidence · Paragraph 7 “…allow aircraft and ships to be tracked by radar.”
Question 7: Multiple Choice
Choose the correct letter, A, B, C or D.
- A. a form of electromagnetic wave with a much longer wavelength than light
- B. a stream of tiny particles thrown out by transmitters
- C. a kind of sound wave that the ear cannot hear
- D. a beam of visible light too faint to see
- 7
According to the passage, what are radio waves?
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Answer: A — a form of electromagnetic wave with a much longer wavelength than light
Why: This is the part of the passage that supports A — a form of electromagnetic wave with a much longer wavelength than light.
Evidence · Paragraph 2 “Both are forms of what scientists call electromagnetic waves ... a radio wave may stretch from a few centimetres to many metres from one crest to the next.”
Questions 8–13: Note Completion
Complete the notes below.
Complete the notes using ONE WORD ONLY from the passage for each answer. How a radio broadcast reaches a listener Radio waves are part of the family of (8) ______ waves. Sound is stamped onto a steady (9) ______ wave. The process of altering the wave is called (10) ______ . The signal is radiated into the air by an (11) ______ . In the receiver, a (12) ______ selects the wanted frequency. Aircraft and ships can be tracked using (13) ______ .
- 8
Radio waves are part of the family of ______ waves.(max 1 word)
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Answer: electromagnetic
Why: The answer “electromagnetic” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 1-word limit.
Evidence · Paragraph 2 “Both are forms of what scientists call electromagnetic waves”
- 9
Sound is stamped onto a steady ______ wave.(max 1 word)
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Answer: carrier
Why: The answer “carrier” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 1-word limit.
Evidence · Paragraph 4 “…a steady radio wave, called a carrier wave, contains no sound at all.”
- 10
The process of altering the wave is called ______ .(max 1 word)
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Answer: modulation
Why: The answer “modulation” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 1-word limit.
Evidence · Paragraph 4 “…a process known as modulation, so that the pattern of the music or speech is stamped upon the wave.”
- 11
The signal is radiated into the air by an ______ .(max 1 word)
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Answer: antenna (also accepted: aerial)
Why: The answer “antenna” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 1-word limit.
Evidence · Paragraph 4 “The altered wave is then fed to an antenna, a length of metal that radiates the signal outward”
- 12
In the receiver, a ______ selects the wanted frequency.(max 1 word)
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Answer: tuner
Why: The answer “tuner” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 1-word limit.
Evidence · Paragraph 5 “A part of the receiver called the tuner selects just one frequency out of this crowd”
- 13
Aircraft and ships can be tracked using ______ .(max 1 word)
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Answer: radar
Why: The answer “radar” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 1-word limit.
Evidence · Paragraph 7 “…allow aircraft and ships to be tracked by radar.”
Estimated band score for this test
Your raw score out of 13 scaled to the 40-question IELTS Reading (Academic) conversion table. This is the same estimate the practice page shows after you submit. A single passage is a small sample, so treat it as a guide.
| Correct answers | Estimated band |
|---|---|
| 13 / 13 | 9.0 |
| 12 / 13 | 8.5 |
| 11 / 13 | 7.5 |
| 10 / 13 | 7.0 |
| 9 / 13 | 6.5 |
| 8 / 13 | 6.0 |
| 7 / 13 | 5.5 |
| 5–6 / 13 | 5.0 |
| 4 / 13 | 4.0 |
| 3 / 13 | 3.5 |
| 2 / 13 | 3.0 |
| 1 / 13 | 2.0 |
| 0 / 13 | 0.0 |
Full-test score? Use the IELTS band calculator.
Tips for the question types in this test
True / False / Not Given
- Read the statement first and underline the key idea, especially any qualifiers like "all", "only", "never", "always", "more than" or dates and numbers.
- Because the questions follow the order of the passage, scan for the paragraph that deals with the same topic rather than re-reading everything.
Common trap: Confusing "False" with "Not Given": choose False only when the passage actively contradicts the statement; if the passage is silent, it is Not Given.
Full True / False / Not Given strategyMultiple Choice
- Read the question stem carefully before the options so you know exactly what is being asked.
- Because multiple-choice questions follow passage order, locate the relevant section and read it in full — the answer usually depends on more than one sentence.
Common trap: Distractors that use exact words from the passage but distort the meaning.
Full Multiple Choice strategyNote Completion
- Use headings and indentation to identify the topic of each blank.
- Predict the answer type and mark the word limit.
Common trap: Treating bullets as unrelated when they belong to one passage section.
Full Note Completion strategyPractise “Radio Waves: The Invisible Messengers” under exam conditions
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