STANDARD Physics Waves Class 11 Questions

Ultrasonic waves produced by a vibrating quartz crystal are

The equation of a progressive wave is given by: y = 5 sin(100 πt − 0.4πx) where y and x are in m and t is in s. (1) The amplitude of the wave is 5 m. (2) The wavelength of the wave is 5 m. (3) The frequency of the wave is 50 Hz. (4) The velocity of the wave is 250 m s⁻¹. Which of the following statements are correct?

A progressive wave is represented by y = 5sin (100πt − 2πx) where x and y are in m and t is in s. The maximum particle velocity is

For the travelling harmonic wave y(x, t) = 2 cos2π(10t − 0.008 x + 0.35) where x and y are in cm and t is in s. The phase difference between oscillatory motion of two points separated by a distance of 0.5 m is

Two waves are represented by y₁ = a sin(ωt + kx + 0.57) and y₂ = a cos(ωt + kx). The phase difference between the two waves is:

The equation of a simple harmonic wave is given by y = 5 sin(π/2 (100t - x)), where x and y are in metre and time is in second. The time period of the wave (in seconds) will be:

A wave travelling along the x-axis is described by the equation y(x, t) = 0.005 sin(αx - βt). If the wavelength and time period of the wave are 0.08 m and 2s respectively, then α, β in appropriate units are:

A transverse wave is represented by y = A sin(ωt-kx). For what value of the wavelength is the wave velocity equal to the maximum particle velocity?

A 10 m long steel wire has mass 5 g. If the wire is under a tension of 80 N, the speed of transverse waves on the wire is

The transverse displacement of a string clamped at its both ends is given by y(x,t) = 0.06sin(\frac{2\pi}{3} x)cos(120\pi t) where x and y are in m, and t in s. The length of the string is 1.5 m and its mass is 3 \times 10^{-2} kg. The tension in the string is

A transverse harmonic wave on a string is described by y(x,t) = 3sin(36t + 0.018x + \frac{\pi}{4}) where x and y are in cm and t is in s. Which of the following statements is incorrect?

Figure given shows a sinusoidal wave on a string. If the frequency of the wave is 150 Hz, what is the velocity and wavelength of the given wave?

If the bulk modulus of water is 2100 MPa, what is the speed of sound in water?

The ratio of the velocity of sound in hydrogen (γ = 7/5) to that in helium (γ = 5/3) at the same temperature is

A hospital uses an ultrasonic scanner to locate tumours in a tissue. The operating frequency of the scanner is 3.2 MHz. The speed of sound in a tissue is 1.6 km s⁻¹. The wavelength of sound in the tissue is

A body sends waves 100 mm long through medium A and 0.25 m long in medium B. If the velocity of waves in medium A is 80 cm s⁻¹. The velocity of waves in medium B is

The stationary wave y = 2a sin kx cos ωt in a stretched string is the result of superposition of y₁ = a sin(kx − ωt) and

A travelling wave represented by y(x, t) = a sin (kx – ωt) is superimposed on another wave represented by y(x, t) = a sin (kx + ωt). The resultant is a

Which of the following statements is correct?

In stationary waves, nodes are the points where there is

In an organ pipe of length L open at both ends, the fundamental mode has a frequency (where v is a speed of sound in air)

The transverse displacement of a string clamped at its both ends is given by y(x, t) = 2sin(2π/3 x)cos(100πt), where x and y are in cm and t is in s. Which of the following statements is correct?

One of the modes of resonance in a tube containing water at one end has been shown. The tube in the present case is in

Two open organs pipes of fundamental frequencies v₁ and v₂ are joined in series. The fundamental frequency of the new pipe so obtained will be

A string fixed at its both ends vibrates in 5 loops as shown in the figure. The total number of nodes and antinodes are respectively

Which of the following statements is incorrect for a stationary wave?

The fundamental note produced by a closed organ pipe is of frequency v. The fundamental note produced by an open organ pipe of same length will be of frequency

A pipe 30 cm long, is open at both ends. Which harmonic mode of the pipe resonates a 1.1 kHz source? (Speed of sound in air = 330 m s⁻¹)

A wire stretched between two rigid supports vibrates in its fundamental mode with a frequency of 50 Hz. The mass of the wire is 30 g and its linear density 4 x 10⁻² kg m⁻¹. The speed of the transverse wave at the string is

A tuning fork A of frequency 512 Hz produces 5 beats per second when sounded with another tuning fork B of unknown frequency. If B is loaded with wax the number of beats is again 5 per second. The frequency of the tuning fork B before it was loaded is

A pipe 17 cm long is closed at one end. Which harmonic mode of the pipe resonates a 1.5 kHz source? (Speed of sound in air = 340 m s⁻¹)

Two sitar strings A and B are slightly out of tune and produce beats of frequency 5 Hz. When the tension in the string B is slightly increased, the beat frequency is found to reduce to 3 Hz. If the frequency of string A is 427 Hz, the original frequency of string B is

Which of the following waves is called heat energy waves?

Water waves produced by a motor boat sailing in water are

Sound waves of wavelength λ travelling in a medium with a speed of v m s⁻¹ enter into another medium where its speed is 2v m s⁻¹. Wavelength of sound waves in the second medium is

Speed of sound wave in air

Which of the following statements is true for wave motion?

Equation of a plane progressive wave is given by y = 0.6 sin 2π (t - x/2). On reflection from a denser medium its amplitude becomes 2/3 of the amplitude of the incident wave. The equation of the reflected wave is

A string of mass 2.5 kg is under a tension of 200 N. The length of the stretched string is 20 m. If the transverse jerk is struck at one end of the string, the disturbance will reach the other end in

The fundamental frequency in an open organ pipe is equal to the third harmonic of a closed organ pipe. If the length of the closed organ pipe is 20 cm, the length of the open organ pipe is

The two nearest harmonics of a tube closed at one end and open at other end are 220 Hz and 260 Hz. What is the fundamental frequency of the system?

A string is clamped at both the ends and it is vibrating in its 4th harmonic. The equation of the stationary wave is Y = 0.3 sin(0.157 x) cos(200 πt). The length of the string is (All quantities are in SI units)

A granite rod of 60 cm length is clamped at its middle point and is set into longitudinal vibrations. The density of granite is 2.7 × 10³ kg m⁻³ and its Young's modulus is 9.27 × 10¹⁰ Pa. What will be the fundamental frequency of the longitudinal vibrations?

Two tuning forks, A and B, produce notes of frequencies f and 260 Hz. If number of beats heard by a person is 8, what can be the possible value of 'f'?

Two vibrating tuning forks produce progressive waves given by Y₁ = 4 sin 500 πt and Y₂ = 2 sin 506 πt. Number of beats produced per minute is: