EASA Part 66 : Physics Question2

Question Number. 20. Tuning forks are used to vibrate musical instruments because. Option A. they produce both of the other effects described. Option B. they produce a beat when played together with the instrument. Option C. they produce a pure note.

Correct Answer is. they produce a pure note. Explanation. A tuning fork produces a pure note, which can be used to tune a guitar (for example) by listening for the beat produced when played alongside an out-of-tune string.

Question Number. 13. Intensity of sound waves. Option A. is not affected by distance. Option B. varies inversely as the square of distance from source. Option C. vary directly as per distance from source.

Correct Answer is. varies inversely as the square of distance from source. Explanation. Sound diminishes with the square of the distance from the source (i.e double the distance = 1/4 the dB, triple the distance = 1/9 the dB etc.) - Technically called a log-linear scale.

Question Number. 38. What is the wavelength of a note of frequency 1kHz when its velocity is 340m/s?. Option A. 3.4m. Option B. 0.34m. Option C. 0.34km.

Correct Answer is. 0.34m. Explanation. V = f λ λ=V/f =340/1000 (answer in SI units of metres).

Question Number. 6. The fundamental frequency is the. Option A. 3rd harmonic. Option B. 1st harmonic. Option C. 2nd harmonic.

Correct Answer is. 1st harmonic.

Question Number. 17. If a tuning fork is struck and held close to the ear and slowly rotated about the vertical axis, in one rotation how many times is there no sound?. Option A. 2. Option B. Sound is audible for the whole revolution. Option C. 4.

Correct Answer is. 2. Explanation. Two sound waves interfere creating a relatively 'dead' zone for approximately 2 quarters of the rotation.

Question Number. 36. The fundamental frequency of a control cable is 10 Hz, the frequency of the 2nd Harmonic is. Option A. 20 Hz. Option B. 20 KHz. Option C. 10 Hz.

Correct Answer is. 20 Hz. Explanation. 2nd harmonic = 2* fundamental frequency.

Question Number. 7. The first overtone of a sound wave is the. Option A. 1st harmonic. Option B. fundamental frequency. Option C. 2nd harmonic.

Correct Answer is. 2nd harmonic.

Question Number. 30. If a string is vibrating at the 3rd harmonic, it will be oscillating at. Option A. Fundamental Frequency. Option B. 4 times its fundamental frequency. Option C. 3 times its fundamental frequency.

Correct Answer is. 3 times its fundamental frequency. Explanation. 1st harmonic = 1 * fundamental frequency. 2nd harmonic = 2 * fundamental frequency. 3rd harmonic = 3 fundamental frequency.

Question Number. 2. The speed of sound in air at 0 °C is approximately. Option A. 331 m/s. Option B. 3 * 108 m/s. Option C. 181 m/s.

Correct Answer is. 331 m/s.

Question Number. 33. The speed of sound at standard atmospheric temperature and pressure is. Option A. 34 Km/s. Option B. 340 m/s. Option C. 340 Km/s.

Correct Answer is. 340 m/s.

Question Number. 12. What frequency is a tone which is 4 times the fundamental frequency?. Option A. 2nd overtone. Option B. 3rd overtone. Option C. 3rd harmonic.

Correct Answer is. 3rd overtone. Explanation. The 4th harmonic is also called the 3rd overtone.

Question Number. 8. Two pure tones of similar frequency are heard by a person. What will they hear?. Option A. One pure tone. Option B. A beat of the two tones. Option C. Two tones.

Correct Answer is. A beat of the two tones. Explanation. At certain points, the troughs cancel the peaks. At other points the peaks 'add to' other peaks. The net effect is a low frequency oscillation in amplitude.".

Question Number. 31. The varying pitch of the sound of a train passing by is caused by a phenomenon known as. Option A. Doppler effect. Option B. double frequency. Option C. resonance.

Correct Answer is. Doppler effect.

Question Number. 18. What is the phenomenon that occurs when a siren that approaches you, at the point of passing, the pitch decreases?. Option A. Resonance. Option B. Doppler effect. Option C. Echo.

Correct Answer is. Doppler effect. Explanation. Doppler effect.

Question Number. 29. A wave in which the vibrations are parallel to, or along, the direction of travel is a. Option A. Transverse Wave. Option B. Upright Wave. Option C. Longitudinal Wave.

Correct Answer is. Longitudinal Wave.

Question Number. 9. Two sound waves of the same frequency and amplitude are moving half a wavelength out of phase with each other. What will be heard?. Option A. Nothing. Option B. Twice the volume of one of the sound waves. Option C. Half the volume of one of the sound waves.

Correct Answer is. Nothing. Explanation. The peaks will cancel the troughs.

Question Number. 1. When the movement of an object rotating around a radius at a constant speed is projected onto a plane, the projected image follows what path?. Option A. Sinusoidal. Option B. Lateral. Option C. Longitudinal.

Correct Answer is. Sinusoidal.

Question Number. 37. Which of the following is an example of a Longitudinal Wave?. Option A. Sound Wave. Option B. Radio Wave. Option C. Light Wave.

Correct Answer is. Sound Wave.

Question Number. 34. In which medium does sound travel the fastest?. Option A. Steel. Option B. Air. Option C. Water.

Correct Answer is. Steel. Explanation. Fastest to slowest - Solid, liquid, gas.

Question Number. 35. Which has the most effect on the speed of sound in air?. Option A. Temperature. Option B. Wavelength. Option C. Frequency.

Correct Answer is. Temperature.

Question Number. 26. A wave in which the vibrations are perpendicular, or at right angles to the direction of wave travel is a. Option A. Dispersion Wave. Option B. Longitudinal Wave. Option C. Transverse Wave.

Correct Answer is. Transverse Wave.

Question Number. 3. If a wave traveling to a point meets a wave traveling from that point, of equal frequency. Option A. the two waves cancel each other out. Option B. they will have no effect on each other. Option C. a standing wave is formed.

Correct Answer is. a standing wave is formed.

Question Number. 14. In a standing wave the point where continuous vibration of maximum amplitude occurs is called the. Option A. harmonic. Option B. anti-node. Option C. node.

Correct Answer is. anti-node. Explanation. The peaks are the anti-nodes. See External website.

Question Number. 27. When a string vibrates, the point at which maximum displacement occurs is called the. Option A. node. Option B. antinode. Option C. primary node.

Correct Answer is. antinode.

Question Number. 10. A fire engine is approaching you with its siren on. As it passes you its pitch. Option A. stay the same. Option B. increases. Option C. decreases.

Correct Answer is. decreases.

Question Number. 32. Wavelength is. Option A. distance from trough to crest. Option B. distance between crests. Option C. distance between top and bottom.

Correct Answer is. distance between crests.

Question Number. 4. Quality of sound depends upon. Option A. pure sound waves being produced by the source. Option B. frequency and harmonics of the waves being produced. Option C. quality of the receiver.

Correct Answer is. frequency and harmonics of the waves being produced.

Question Number. 24. The amplitude of a Transverse Wave is the distance from. Option A. the top of a peak to the bottom of a trough. Option B. half the distance from peak to trough. Option C. one peak to the next.

Correct Answer is. half the distance from peak to trough.

Question Number. 16. The speed of sound in dry air is 331 m/s. In a solid the speed would. Option A. increase. Option B. decrease. Option C. stay the same.

Correct Answer is. increase. Explanation. Speed of sound is greater in a solid than in air.

Question Number. 15. The name given to sounds below that which the human ear can detect, i.e. below 20Hz is. Option A. ultra sound. Option B. infra sound. Option C. sonic pitch. .

Correct Answer is. infra sound. Explanation. See how silent thunder can shatter windows at External website

Question Number. 25. Increasing the Amplitude of a sound wave increases its. Option A. pitch. Option B. moment. Option C. loudness.

Correct Answer is. loudness.

Question Number. 23. In a vibrating string, the point at which there is no displacement is called a. Option A. antinode. Option B. node. Option C. fundamental mode.

Correct Answer is. node.

Question Number. 11. Quality of sound is dependant on. Option A. number and pitch of harmonics. Option B. medium it is traveling through. Option C. frequency of the supply.

Correct Answer is. number and pitch of harmonics. Explanation. Quality of sound is dependant upon the number of harmonics and the pitch.

Question Number. 19. For hearing protection, noise cancelling headphones. Option A. cannot reduce the noise from outside completely. Option B. operate by destructive interference of sound waves. Option C. operate by constructive interference of sound waves.

Correct Answer is. operate by destructive interference of sound waves.

Question Number. 28. Increasing the frequency of a sound wave increases its. Option A. pitch. Option B. loudness. Option C. moment.

Correct Answer is. pitch.

Question Number. 5. Particles vibrating in air. Option A. tend to give off heat. Option B. tend to give off light. Option C. produce waves.

Correct Answer is. produce waves. Explanation. Particles vibrating in air produce sound.

Question Number. 21. When an open pipe is played and a note is heard. Option A. the lowest frequency of the note is called second harmonic. Option B. resonance occurs with standing waves set up inside the pipe. Option C. there is a 180º phase change at the open end.

Correct Answer is. resonance occurs with standing waves set up inside the pipe.

Question Number. 22. Two sound waves are the same but slightly out of phase. This means that. Option A. the beat frequency is the same. Option B. there will be no beat frequency. Option C. the beat frequency will be slightly different.

Correct Answer is. the beat frequency is the same. Explanation. The beat frequency is the same frequency as either of the two frequencies.