NEET Physics Waves Class 11 Questions

If a wave gets refracted into a denser medium, then which of the following is true?

A pipe open at both ends has fundamental frequency f in air. The pipe is dipped vertically in water so that half of it is in water. The fundamental frequency of the air column is now

The phase difference between oscillatory motion of two points separated by a distance of \( \frac{\lambda}{2} \) is (where \( \lambda \) is the wavelength)

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

In the wave equation \( y = 0.5 \sin \left( \frac{2\pi}{\lambda} (400t - x) \right) \) the velocity of the wave will be :

Tick the correct:

In stationary waves, nodes are the points where there is

The displacement of a string is given by y(x, t) = 0.06sin(\(\frac{2\pi x}{3}\)cos(120πt)), where x and y are in metre and t in second. The length of the string is 1.5 m and its mass is 3.0 × 10⁻² kg.

The temperature at which the speed of sound in air becomes double of its value at 0°C is

Statement^{-1}: A steel wire with mass per unit length 7.0 × 10⁻³ kg m⁻¹ is under tension of 70 N. The speed of transverse waves in the wire = 100 m/s. Statement^{-2}: For a solid rod, the Young's modulus of elasticity is 3.2 × 10¹¹ N m⁻² and density is 8 × 10³ kg m⁻³. The velocity of longitudinal wave in the rod = 2 × 10³.

A pulse is generated at lower end of a hanging rope of uniform density and length L. The speed of the pulse when it reaches the mid point of the rope is

An organ pipe closed at one end has fundamental frequency of 1500 Hz. The maximum number of overtones generated by this pipe which a normal person can hear is

A string 2.0 m long and fixed at its end is driven by a 240 Hz vibrator. The string vibrates in its third harmonic mode. The speed of the wave and its fundamental frequency is-

Two tuning forks A and B are sounded together giving rise to 8 beats in 2 s. When fork A is loaded with wax, the beat frequency is reduced to 4 beats in 2 s. If the original frequency of tuning fork B is 380 Hz then original frequency of tuning fork A is _____ Hz.

For a travelling harmonic wave y(x, t) = 2.0 cos 2π(10t − 0.0080x + 0.35), where x and y are in cm and t in s. The phase difference between oscillatory motion of two points separated by a distance of 0.5 m is:

A pipe open at both ends has a fundamental frequency f in air. The pipe is now dipped vertically in a water drum to half of its length. The fundamental frequency of the air column is now equal to:

The ratio of frequencies of fundamental harmonic produced by an open pipe to that of closed pipe having the same length is:

If the initial tension on a stretched string is doubled, then the ratio of the initial and final speeds of a transverse wave along the string is:

In a guitar, two strings A and B made of same material are slightly out of tune and produce beats of frequency 6 Hz. When tension in B is slightly decreased, the beat frequency increases to 7 Hz. If the frequency of A is 530 Hz, the original frequency of B will be:

A tuning fork is used to produce resonance in a glass tube. The length of the air column in this tube can be adjusted by a variable piston. At room temperature of 27 °C two successive resonances are produced at 20 cm and 73 cm of column length. If the frequency of the tuning fork is 320 Hz, the velocity of sound in air at 27 °C is

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

A particle executes linear simple harmonic motion with amplitude of 3 cm. When the particle is at 2 cm from the mean position, the magnitude of its velocity is equal to that of its acceleration. Then its time period in seconds 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?

Two cars moving in opposite directions approach each other with speed of 22 m/s and 16.5 m/s respectively. The driver of the first car blows a horn having a frequency 400 Hz. The frequency heard by the driver of the second car is (velocity of sound 340 m/s)

A uniform rope of length L and mass m₁ hangs vertically from a rigid support. A block of mass m₂ is attached to the free end of the rope. A transverse pulse of wavelength λ₁ is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is λ₂. The ratio λ₂/λ₁ is

An air column, closed at one end and open at the other, resonates with a tuning fork when the smallest length of the column is 50 cm. The next larger length of the column resonating with the same tuning fork is

A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of 15 m s⁻¹. Then, the frequency of sound that the observer hears in the echo reflected from the cliff is (Take velocity of sound in air = 330 m s⁻¹)

The fundamental frequency of a closed organ pipe of length 20 cm is equal to the second overtone of an organ pipe open on both ends. The length of organ pipe open at both the ends is

The number of possible natural oscillations of air column in the pipe closed at one end of length 85 cm whose frequencies lie below 1250 Hz. are (Velocity of sound = 340 m/s.)

A speeding motorcyclist sees traffic jam ahead of him. He slows down to 36 km/hour. He finds that traffic has eased and a car moving ahead of him at 18 km/hour is honking at a frequency of 1392 Hz. If the speed of sound is 343 m/s, the frequency of the honk as heard by him will be

If n₁, n₂ and n₃ are the fundamental frequencies of three segments into which a string is divided then the original fundamental frequency n of the string is given by

The length of the wire between two ends of a sonometer is 100 cm. What should be the positions of two bridges below the wire so that the three segments of the wire have their fundamental frequencies in the ratio 1 : 3 : 5

Two sources P and Q produce notes of frequency 660 Hz each. A listener moves from P to Q with a speed of 1 m s⁻¹. If the speed of sound is 330 m/s, the number of beats heard by the listener per second will be: