intro
Question 1:
What would be the velocity of sound at a temperature where it is twice its velocity at 0˚C?
Topic: Temperature and Velocity of Sound
Correct Answer: C) 819˚C
- The velocity of sound increases with an increase in temperature.
- Given that at 0˚C, the velocity is 332ms-1, the question asks at what temperature it will be twice that i.e., 664ms-1.
- The relationship between the velocity of sound and temperature generally follows the formula v = 331.4 + 0.6T, where v is the velocity and T is the temperature in Celsius.
- Solving the equation 664 = 331.4 + 0.6T gives T as approximately 819°C.
- Hence, the correct answer is C, "819˚C".
Question 2:
What would be the outcome on the velocity of the resultant wave when two matching traveling waves overlay on each other?
Topic: Wave Superposition and Velocity
Correct Answer: C) The velocity remains the same
- The question deals with the superposition of two identical traveling waves.
- Whenever waves overlap, the result is a wave that's the sum of all of the waves.
- However, the velocity of the resultant wave remains unchanged as it is independent of the superposition.
- Therefore, the correct answer is C, "The velocity remains the same".
Question 3:
What happens to the perceived frequency or pitch of the sound when the sound source is moving towards a stationary listener?
Topic: Doppler Effect and Sound Frequency
Correct Answer: B) It’s higher than the original sound frequency
- This question explores the Doppler Effect related to sound waves.
- When a sound source moves towards a stationary listener, the apparent frequency of the sound perceived by the listener increases.
- This is because the sound waves are compressed, leading to a higher pitch.
- Thus, the correct answer is B, "It’s higher than the original sound frequency".
Question 4:
Which of the following components are present in a stationary wave?
Topic: Stationary Waves and their Components
Correct Answer: C) Nodes and antinodes
- Standing waves are characterized by nodes and antinodes, which are points on the wave.
- Nodes are points of zero displacement, while antinodes are points of maximum displacement.
- Therefore, the correct response is C, "Nodes and antinodes".
Question 5:
What are the endpoints of a resonating string referred to as?
Topic: Properties of a Vibrating String
Correct Answer: A) Nodes
- In the context of a string vibrating, the fixed ends are known as nodes.
- Wave nodes are zero displacement points on a wave.
- This occurs at the fixed ends of a vibrating string, as these points don't move.
- Therefore, the correct answer is A, "Nodes".
Question 6:
Given a string that is 3m long and vibrates forming 3 loops, and the wave speed is 30m/s, what is the frequency of the vibration?
Topic: String Vibration and Frequency
Correct Answer: C) 15Hz
- The question describes a scenario involving wave frequency on a vibrating string.
- The formula to calculate the frequency of a standing wave on a string is fn = nv/2l.
- Substituting the given values into the equation ((330)/(23)) yields a frequency of 15Hz.
- Therefore, the correct answer is C, "15Hz".
Question 7:
If a string is portioned into three sections, such that each segment's fundamental frequencies are in the ratio 1:2:3, what would be the correlation between the lengths of the segments?
Topic: String Length and Fundamental Frequency
Correct Answer: D) 3:2:1
- The question relates to the relationship between the length of a string and its frequency.
- A vibrating string's fundamental frequency is inversely proportional to its length.
- Thus, if the fundamental frequencies are in the ratio 1:2:3, the lengths of the segments would be in the inverse ratio, which is 3:2:1.
- Hence, the correct answer is D, "3:2:1".
Question 8:
What would be the velocity of sound in air at a temperature of 10˚C?
Topic: Temperature and Sound Velocity
Correct Answer: C) 338.1ms-1
- This question involves understanding the relationship between air temperature and the speed of sound.
- The formula to calculate the speed of sound in air at a given temperature is Vt = V0 + 0.61t.
- By substituting the temperature value into the equation ((332 + 0.61 * 10)), we get a speed of 338.1ms-1.
- Therefore, the correct answer is C, "338.1ms-1".
Question 9:
Of the following wave properties, which one is not influenced by the remaining properties?
Topic: Independent Wave Properties
Correct Answer: C) Amplitude
- While frequency, wavelength, and velocity are interconnected, the amplitude of a wave operates independently, not influenced by these three parameters.
- Hence, the correct answer is C, "Amplitude".
Question 10:
What is the proportionality of the sound's velocity in 4 atmospheres relative to its velocity in 1 atmosphere?
Topic: Effects of Pressure on Sound Velocity
Correct Answer: C) 1:1
- It is important to note that pressure variations don't affect the velocity of sound.
- Therefore, the ratio of the speed of sound at 4 atmospheres to that at 1 atmosphere remains unchanged, i.e., 1:1.
- Thus, the correct answer is C, "1:1".
Question 11:
Which type of waves necessitates a medium for propagation?
Topic: Wave Propagation and Mediums
Correct Answer: B) Mechanical waves
- Mechanical waves are distinct in that they require a medium (such as air, water, or solids) for propagation.
- Therefore, the correct answer is B, "Mechanical waves".
Question 12:
Given a stationary wave with a frequency of 165Hz and the speed of sound in air being 330m/s, what is the distance between two successive nodes?
Topic: Stationary Waves and Node Distance
Correct Answer: C) 1 m
- The formula for the wavelength of a wave is λ = v/f. The distance between two consecutive nodes is half the wavelength.
- So, by substituting the frequency and velocity of sound into the equation, we get a result of 2m for the wavelength, implying a node distance of 1m.
- Thus, the correct answer is C, "1 m".
Question 13:
If a taut string measuring 4m forms 4 loops when stationary waves are produced, what is the wavelength of the waves?
Topic: Stationary Waves and Wavelength
Correct Answer: B) 2m
- The wavelength is twice the length of one loop.
- If 4 loops are formed in a 4m string, each loop is 1m long.
- Thus, the wavelength of the waves would be 2m.
Question 14:
Which of the following properties is not characteristic of sound waves in air?
Topic: Characteristics of Sound Waves
Correct Answer: D) Polarization
- All wave properties, such as Deflection, Diffraction, and Refraction, apply to sound waves except for Polarization, which is unique to transverse waves.
Question 15:
In a pipe system that is closed at one end, what is the proportion of nodes to antinodes?
Topic: Nodes and Antinodes in a Closed Pipe System
Correct Answer: C) Equal to one
- This question examines the understanding of nodes and antinodes in a closed pipe system.
- In a pipe that is closed at one end, the ratio of nodes to antinodes always equals one.
- Thus, the correct answer is C, "Equal to one".
Question 16:
What is the correct relationship between the fundamental frequencies of an open organ pipe and a closed organ pipe?
Topic: Fundamental Frequencies of Organ Pipes
Correct Answer: A) f (open) = 2f (closed)
- This question tests the understanding of the fundamental frequencies in different organ pipes.
- An open organ pipe has both ends open, allowing it to produce a frequency twice that of a closed organ pipe, hence f (open) = 2f (closed).
- Therefore, the correct answer is A, "f (open) = 2f (closed)".
Question 17:
What is the determining factor for change in frequency according to the Doppler effect?
Topic: Factors Influencing Doppler Effect
Correct Answer: B) Velocity of both the source and the receiver
- The Doppler effect stipulates that the apparent frequency change is primarily dependent on the relative motion between the source and observer.
- This is determined by their respective speeds.
- Hence, the correct answer is B, "Velocity of both the source and the receiver".
Question 18:
A source "S" at rest generates circular waves on a lake with a wave speed of 5.0 m/s and a distance between crests of 2.0m. A person on a speedboat approaches the source at a speed of 3.0 m/s. What is the frequency of the waves perceived by this person?
Topic: Perception of Wave Frequency
Correct Answer: D) 4.0 Hz
- For a moving observer approaching the source, there will be a higher frequency encountered due to shortened wave intervals.
- Therefore, the correct answer is D, "4.0 Hz".
Question 19:
What types of wave can mechanical waves be?
Topic: Types of Mechanical Waves
Correct Answer: C) Both longitudinal and transverse
- Mechanical waves can manifest as either longitudinal or transverse waves, or sometimes both.
- Thus, the correct answer is C, "Both longitudinal and transverse".
Question 20:
Given a sound speed of 340 m/s, what would be the length of the smallest closed pipe that would resonate at a frequency of 100Hz?
Topic: Resonance in Closed Pipes
Correct Answer: D) 85 cm
- This problem assesses understanding of resonance in closed pipes and the relationship between speed, frequency, and wavelength.
- The shortest closed pipe resonating at a specific frequency would be equivalent to the length of the wave at the first harmonic.
- Therefore, the correct answer is D, "85 cm".
Question 23:
If the velocity of sound at freezing point (0˚C) is denoted as v0, how would one describe the velocity when the temperature is 273˚C?
Topic: Sound Speed and Temperature
Correct Answer: D) 70% of the initial velocity (0.7v0)
- This question examines the knowledge of the relationship between sound velocity and temperature.
- The velocity of sound varies with temperature, increasing as the temperature rises, but not linearly.
- As such, the correct answer is D, "70% of the initial velocity".
Question 24:
What physics principle is used in determining the velocity of celestial bodies such as stars and galaxies?
Topic: Velocity Measurement of Celestial Bodies
Correct Answer: B) Doppler’s effect
- This question evaluates the understanding of the Doppler Effect and its applications in astronomy.
- The Doppler Effect is used by astronomers to calculate the velocity of stars and galaxies by comparing the spectrum of their light with a known light source.
- Therefore, the correct answer is B, "Doppler’s effect".
Question 25:
Given that 30 waves pass through a certain medium every second at a speed of 30 m/s, how would you calculate the wavelength of the waves?
Topic: Calculating Wavelength
Correct Answer: B) 1 m
- This question tests understanding of wave calculations, specifically the relationship between frequency, speed, and wavelength.
- Wavelength can be calculated by dividing the speed of the wave by its frequency.
- Thus, the correct answer is B, "1 m".
Question 26:
What type of spectral shift is observed from stars that are receding from the Earth?
Topic: Celestial Bodies and Spectral Shifts
Correct Answer: C) Red shift
- This question tests the comprehension of the Doppler Effect in relation to celestial motion.
- Stars moving away from the Earth exhibit a red shift due to the stretching of light waves. This is a consequence of the Doppler Effect.
- Consequently, the correct answer is C, "Red shift".
Question 27:
What happens to the perceived wavelength and frequency of sound when its source is moving away from an observer who is stationary?
Topic: Doppler Effect on Sound
Correct Answer: D) Both A and B
- This question probes understanding of the Doppler Effect in relation to sound propagation.
- When the source of sound moves away from an observer, there is an apparent increase in wavelength and a decrease in frequency due to the stretching of sound waves.
- Hence, the correct answer is D, "Both A and B".
Question 28:
In which of the following forms does sound propagate the fastest?
Topic: Sound Propagation in Different Mediums
Correct Answer: A) Solid
- This question evaluates understanding of sound speed in various media.
- Sound propagates fastest in solids due to greater elasticity and closer particle arrangement.
- Therefore, the correct answer is A, "Solid".
MCQ 29:
What is the impact on the speed of sound in a gas if the pressure of that gas is doubled?
Topic: Sound Speed and Gas Pressure
Correct Answer: C) It remains the same
- This query tests comprehension of the relationship between sound speed and gas pressure.
- Despite common misconceptions, the speed of sound in a gas is independent of the pressure. Therefore, even if the pressure is doubled, the speed of sound remains the same.
- As a result, the correct answer is C, "It remains the same".
MCQ 30:
Which types of waves does the Doppler Effect apply to?
Topic: Scope of the Doppler Effect
Correct Answer: D) Both mechanical and electromagnetic waves
- This question gauges understanding of the applicability of the Doppler Effect.
- The Doppler Effect is universal and applies to both mechanical waves (like sound waves), and electromagnetic waves (like light waves).
- Consequently, the correct answer is D, "Both mechanical and electromagnetic waves".
Question 31:
What occurs when two identical waves with the same frequency, moving in opposite directions, meet at the same point at the same time?
Topic: Meeting of Identical Waves
Correct Answer: B) Stationary waves are generated
- This question evaluates understanding of wave interactions, particularly when two identical waves meet.
- When two identical waves of the same frequency moving in opposite directions meet at the same point simultaneously, stationary waves are produced.
- Therefore, the correct answer is B, "Stationary waves are generated".
Question 32:
An observer is approaching a stationary sound source with a speed of v/3. If v represents the speed of sound and f is the initial frequency, what would the apparent frequency be?
Topic: Apparent Frequency and Motion of Observer
Correct Answer: A) (4/3) f
- This question tests understanding of the Doppler Effect, particularly how the motion of the observer affects the perceived frequency.
- A stationary sound source appears to increase in frequency as the observer moves towards it. The observer's speed is a factor in this change, with the apparent frequency being (v+v/3)/v of the original frequency, which simplifies to (4/3)f.
- Therefore, the correct answer is A, "(4/3) f".
Question 33:
Which concept can be utilized to determine the velocity of a star relative to the Earth?
Topic: Velocity Estimation of Stars
Correct Answer: A) Doppler's effect
- This question gauges understanding of the applications of various wave phenomena, with a specific focus on the Doppler Effect.
- The Doppler Effect is instrumental in astronomical observations and can be used to determine the velocity of a star relative to Earth by analyzing shifts in the star's spectral lines.
- As a result, the correct answer is A, "Doppler's effect".
Question 34:
Shown below are four scenarios where a sound source "S" with frequency "f" and a detector "D" may be in motion or stationary. It is indicated by arrows that the movement is in the same direction and the speed is the same. Detector 3 is static. The detected frequency is the same. Arrange the scenarios in order of observed frequency at detector D, from lowest to highest.
Topic: Frequency Observation in Different Scenarios
Correct Answer: A) 1,2,3,4
- This question assesses understanding of the Doppler Effect, particularly how the motion of both the source and the observer affect the observed frequency.
- The key to solving this question is understanding how motion towards or away from the source affects the observed frequency.
- Therefore, the correct answer is A, "1,2,3,4".
Question 35:
What is the term for a set of frequencies that are multiples of a fundamental frequency?
Topic: Harmonics and Fundamental Frequencies
Correct Answer: D) Harmonics
- This question tests understanding of fundamental frequencies and their relationship to other frequencies in a system.
- Harmonics and overtones are frequencies that are integral multiples of the fundamental frequency. It is only possible to set up a stationary wave with discrete frequencies (f1, 2f1, 3f1, 4f1... nf1).
- Therefore, the correct answer is D, "Harmonics".