intro
Question 1:
What are the possible frequencies in an open organ pipe, if the fundamental frequency is represented by 'f'?
Topic: Frequency Patterns in Open Organ Pipes
Correct Answer: A) 2f, 3f, 4f
- This question pertains to the understanding of frequency patterns in open organ pipes, where 'f' represents the fundamental frequency.
- In this case, the subsequent frequencies follow a sequence of f, 2f, 3f, 4f, making option A the correct answer.
- It's important to remember that for open organ pipes, the frequencies produced are integral multiples of the fundamental frequency, a characteristic also known as harmonic series.
Question 2:
Compared to oxygen, how fast does sound travel in hydrogen?
Topic: Speed of Sound in Different Gases
Correct Answer: C) Four times faster
- The speed of sound in gases is determined by their elastic properties and density.
- Hydrogen and oxygen possess similar elastic properties, but hydrogen is less dense.
- Consequently, sound travels approximately four times faster in hydrogen compared to oxygen.
Question 3:
An organ pipe open at both ends produces a fundamental frequency of 400Hz. What will be the fundamental frequency if one end is closed?
Topic: Frequency Variation in Organ Pipes
Correct Answer: D) 200 Hz
- The frequency of a pipe with both ends open is double that of a pipe with one end closed.
- If the frequency with both ends open is 400Hz, the frequency with one end closed will be half of that, i.e., 200Hz.
Question 4:
What can the Doppler effect be used to calculate?
Topic: Applications of the Doppler Effect
Correct Answer: D) Speed of galaxies
- In the realm of astronomy, the Doppler effect is invaluable and can result in a redshift or blueshift of electromagnetic waves like light.
- It's used to measure the speed at which stars and galaxies move towards or away from us, i.e., their radial velocities.
Question 5:
Among the choices given, which one is an example of a transverse wave?
Topic: Types of Waves
Correct Answer: C) String vibrations
- When we talk about waves, it's crucial to differentiate between transverse and longitudinal waves.
- Sound waves, for instance, are longitudinal, meaning they travel parallel to the direction of the medium through which they travel.
- In contrast, a vibrating string generates transverse waves that propagate perpendicularly to the direction of displacement.
- Therefore, the correct answer is "C) String vibrations".
Question 6:
In which of these scenarios would the Doppler effect not apply?
Topic: Limitations of the Doppler Effect
Correct Answer: D) Tuning a musical instrument
- The Doppler effect is an essential concept in physics that explains the perceived wavelength and frequency change of a wave in relation to the observer's motion.
- However, this effect does not apply when tuning a musical instrument, as this process primarily involves creating beat frequencies and matching resonant frequencies.
- Thus, the correct answer is "D) Tuning a musical instrument".
Question 7:
What is the phenomenon observed when stars are moving away from the Earth?
Topic: Doppler Effect in Astronomy
Correct Answer: A) Redshift
- The shift in the observed wavelength and frequency of waves due to motion of the source relative to the observer is popularly known as the Doppler Effect, and it has significant applications in astronomy.
- When stars recede from the Earth, we observe a redshift, characterized by an increase in wavelength or a shift of light to the longer-wavelength (red) end of the spectrum.
- Therefore, the correct answer is "A) Redshift".
Question 8:
Which type of waves can also be referred to as pressure waves?
Topic: Types of Waves
Correct Answer: B) Longitudinal waves
- Pressure waves, also referred to as longitudinal waves, move through a medium by causing particles to oscillate to and fro in the direction of energy transport.
- This oscillation results in areas of compression and rarefaction, creating pressure changes within the medium.
- Hence, the correct answer is "B) Longitudinal waves".
Question 9:
What happens to the speed of wave propagation when the tension in a stretched string is quadrupled?
Topic: Wave Propagation
Correct Answer: C) Doubles
- The speed of a wave traveling along a stretched string depends on the square root of the tension force.
- Therefore, when the tension is quadrupled, the wave speed doubles, not quadruples.
- Therefore, the correct answer is "C) Doubles".
Question 10:
What is the phase difference between particles situated on either side of a nodal point in a wave?
Topic: Wave Properties
Correct Answer: C) 180°
- During standing waves, nodes are points where the wave amplitude is at its minimum, and particles are resting there.
- The phase difference between particles on either side of a node is 180°, indicating that they are in antiphase.
- Therefore, the correct answer is "C) 180°".
Question 11:
What is the resultant when the time period of a wave is multiplied by its frequency?
Topic: Wave Characteristics
Correct Answer: D) 1
- The frequency of a wave is the reciprocal of its time period (f = 1/T).
- Consequently, when you multiply the frequency (f) by the time period (T), you get a constant value of 1.
- Hence, the correct response is "D) 1".
Question 12:
What is the effect on the frequency of stationary waves if the linear mass density of a wire doubles?
Topic: Characteristics of Stationary Waves
Correct Answer: C) Decreases by 0.7 times
- The frequency of stationary waves depends on the linear mass density of the medium in which they are created.
- When the mass per unit length of the medium doubles, the frequency of the waves decreases by about 0.7 times.
- Therefore, the correct option is "C) Decreases by 0.7 times".
Question 13:
A wave has a wavelength of 1 meter and a period of 2 seconds. What is its velocity?
Topic: Wave Velocity
Correct Answer: B) 0.5 m/s
- A wave's speed can be calculated by dividing its wavelength by its period (v = λ/T).
- In this case, with a wavelength of 1 meter and a period of 2 seconds, the wave's speed is 0.5 m/s.
- Hence, the correct answer is "B) 0.5 m/s".
Question 14:
An organ pipe is 20 meters long and the speed of the waves generated in it is 25 m/s. What would be the frequency of the fifth harmonic if one end of the organ pipe is closed?
Topic: Harmonics in Organ Pipes
Correct Answer: C) 2.8 Hz
- In an organ pipe with one end closed, the fifth harmonic corresponds to the ninth overtone.
- The frequency of this harmonic can be calculated using the formula: f = nv/4L, where n=9 (for the fifth harmonic), v= speed of the waves, and L= length of the pipe.
- Substituting the given values, we find that the frequency is approximately 2.8 Hz.
- Therefore, the correct answer is "C) 2.8 Hz".
Question 15:
What is the distance between the nearest node and antinode in a standing wave?
Topic: Properties of Standing Waves
Correct Answer: C) λ/4
- In a standing wave, nodes are points of minimum amplitude while antinodes are points of maximum amplitude.
- The distance between any node and its nearest antinode is always one-fourth of the wavelength (λ/4).
- Thus, the correct answer is "C) λ/4".
Question 16:
What is the velocity of the particles at the nodal points in a standing wave?
Topic: Characteristics of Standing Waves
Correct Answer: A) Zero
- A node in a standing wave is a point where the amplitude of the wave is minimum, essentially a point of no displacement.
- At these nodal points, the particles of the medium through which the wave is traveling are at rest.
- Therefore, their velocity is zero.
- Hence, the correct answer is "A) Zero".
Question 17:
What kind of waves are created by a motorboat cruising in water?
Topic: Wave Types
Correct Answer: C) Both transverse and longitudinal
- A motorboat moving through water generates waves of both types - transverse and longitudinal.
- Transverse waves are observed on the water's surface while longitudinal waves occur deeper in the water.
- Therefore, the right answer is "C) Both transverse and longitudinal".
Question 18:
If the tension in a wave medium is quadrupled, what happens to the frequency of the waves, given the initial frequency is 200Hz?
Topic: Wave Frequency and Tension
Correct Answer: C) Increases to 400 Hz
- The frequency of a wave is directly related to the square root of the tension in the medium.
- So, if the tension is increased four times, the frequency is doubled.
- Therefore, the frequency increases to 400Hz.
- Hence, the correct option is "C) Increases to 400 Hz".
Question 19:
Which wave from the following list is an example of a longitudinal wave?
Topic: Longitudinal Waves
Correct Answer: A) Sound waves
- Longitudinal waves have their oscillations parallel to the direction of wave propagation.
- Sound waves are a prime example of such waves, where the air particles vibrate back and forth in the same direction as the wave is moving.
- Therefore, the correct answer is "A) Sound waves".
Question 20:
What characteristic distinguishes a progressive wave from a standing wave?
Topic: Progressive vs Standing Waves
Correct Answer: B) Energy Transfer
- An important distinction between progressive and stationary waves lies in the propagation of energy.
- In a stationary wave, each particle vibrates independently and energy is not transferred forward.
- In contrast, in a progressive wave, all particles move with max velocity at the mean position, resulting in onward energy propagation.
- Hence, the correct answer is "B) Energy Transfer".
Question 21:
A source of sound is moving towards a stationary listener at one-tenth the speed of sound. What is the ratio of apparent frequency to actual frequency?
Topic: Doppler Effect
Correct Answer: B) 10:9
- Due to the Doppler Effect, the frequency of sound appears different to a stationary observer when the source of sound is moving towards or away from the observer.
- In this case, as the source of sound is moving towards the listener, the apparent frequency will be higher than the real frequency.
- The ratio of apparent frequency to real frequency is 10:9.
- Therefore, the correct answer is "B) 10:9".
Question 22:
A stationary wave vibrates in four segments at a frequency of 120Hz. What is its basic frequency?
Topic: Fundamental Frequency
Correct Answer: B) 30 Hz
- The fundamental frequency of a stationary wave can be calculated by dividing the given frequency by the number of segments.
- In this case, the given frequency is 120Hz and the wave vibrates in 4 segments.
- So, the fundamental frequency is 120Hz divided by 4, which equals 30Hz.
- Therefore, the correct answer is "B) 30 Hz".
Question 23:
What happens to the fundamental frequency of a sonometer's wire if its tension is amplified by a factor of four?
Topic: Fundamental Frequency and Tension
Correct Answer: A) It doubles
- In a sonometer, the fundamental frequency is directly proportional to the tension squared.
- Hence, when the tension increases fourfold, the fundamental frequency doubles.
- Thus, the correct answer is "A) It doubles".
Question 24:
Which characteristic of sound is influenced by a variation in air temperature?
Topic: Sound Properties and Temperature
Correct Answer: A) Wavelength
- Sound speed varies directly as a function of absolute temperature and frequency, and wavelength varies as a function of frequency.
- Therefore, since frequency remains constant, if temperature changes, the wavelength will also change.
- Hence, the correct answer is "A) Wavelength".
Question 25:
To whom does the Doppler Effect apply?
Topic: Doppler Effect
Correct Answer: C) In the context of relative motion
- When viewed from a moving point of view, a wave's frequency or wavelength changes due to the Doppler Effect.
- As a result, it applies to situations in which the source and observer are moving relative to one another.
- Thus, the correct answer is "C) In the context of relative motion".
Question 26:
How do bats find their way and locate their meal?
Topic: Echolocation in Bats
Correct Answer: C) Echolocation
- Bats, especially those hunting in dark environments, use a method known as echolocation to navigate and search for food.
- A bat uses this technique to identify objects by sending out sound waves that bounce off them.
- Therefore, the correct answer is "C) Echolocation".
Question 27:
A person at the center of a circle observes a whistle spinning rapidly in a horizontal circle with a radius R. How would the frequency of the whistle sound to the observer?
Topic: Sound Frequency and Motion
Correct Answer: D) Constant
- Given that the observer is at the center and the whistle is rotating around them, the distance between the observer and the whistle remains constant over time.
- As such, there is no change in the frequency of the whistle sound as perceived by the observer.
- Therefore, the correct answer is "D) Constant".
Question 28:
What are the frequencies that would be generated if a closed organ pipe with a fundamental frequency of 100Hz is opened at its other end?
Topic: Frequencies in Organ Pipes
Correct Answer: A) 200, 400, 600, 800
- When an organ pipe is closed at one end and open at the other, the fundamental frequency (first harmonic) is established.
- As the pipe is opened at the other end as well, the frequency doubles, and the harmonic series changes.
- Therefore, the frequencies produced would be multiples of the open end frequency, which are 200, 400, 600, and 800.
- Therefore, the correct answer is "A) 200, 400, 600, 800".
Question 29:
If the fundamental frequency in a stretched string is 100Hz, what change in tension would be required to double the frequency?
Topic: Frequency and Tension of Stretched Strings
Correct Answer: C) T2 = 4T1
- A stretched string's fundamental frequency is proportional to its tension squared.
- Therefore, to double the frequency, the tension should be quadrupled.
- Hence, the correct answer is "C) T2 = 4T1".
Question 30:
What is the most fundamental property of a wave?
Topic: Fundamental Properties of Waves
Correct Answer: C) Frequency
- The frequency of a wave remains constant, even when the wave travels from one medium to another, where its wavelength and velocity may change.
- Therefore, frequency is considered the most fundamental property of a wave.
- Thus, the correct answer is "C) Frequency".