The frequency of a stretched uniform wire under tension is in resonance with the fundamental frequency of a closed tube. If the tension in the wire is increased by 8 N, it is in resonance with the first overtone of the closed tube. The initial tension in the wire is

(1) 1 N

(2) 4 N

(3) 8 N

(4) 16 N

Concept Questions :-

Travelling wave on string
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A metal wire of linear mass density of 9.8 g/m is stretched with a tension of 10 kg weight between two rigid supports 1 metre apart. The wire passes at its middle point between the poles of a permanent magnet, and it vibrates in resonance when carrying an alternating current of frequency n. The frequency n of the alternating source is :

(1) 25 Hz

(2) 50 Hz

(3) 100 Hz

(4) 200 Hz

Concept Questions :-

Travelling wave on string
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

An open pipe is in resonance in its 2nd harmonic with tuning fork of frequency f1. Now it is closed at one end. If the frequency of the tuning fork is increased slowly from f1 , then again a resonance is obtained with a frequency f2. If in this case the pipe vibrates in ${n}^{th}$ harmonic, then -

(1) n = 3, ${f}_{2}=\frac{3}{4}{f}_{1}$

(2) n = 3, ${f}_{2}=\frac{5}{4}{f}_{1}$

(3) n = 5, ${f}_{2}=\frac{5}{4}{f}_{1}$

(4) n = 5, ${f}_{2}=\frac{3}{4}{f}_{1}$

Concept Questions :-

Doppler effect
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Two loudspeakers L1 and L2 driven by a common oscillator and amplifier, are arranged as shown. The frequency of the oscillator is gradually increased from zero and the detector at D records a series of maxima and minima. If the speed of sound is 330 ms–1 then the frequency at which the first maximum is observed is

(1) 165 Hz

(2) 330 Hz

(3) 496 Hz

(4) 660 Hz

Concept Questions :-

Doppler effect
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A string of length L and mass M hangs freely from a fixed point. Then the velocity of transverse waves along the string at a distance x from the free end is

(1) $\sqrt{gL}$

(2) $\sqrt{gx}$

(3) gL

(4) gx

Concept Questions :-

Travelling wave on string
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Three waves of equal frequency having amplitudes 10 μm, 4 μm and 7 μm arrive at a given point with a successive phase difference of $\frac{\pi }{2}$. The amplitude of the resulting wave in μm is given by

(1) 7

(2) 6

(3) 5

(4) 4

Concept Questions :-

Standing waves
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

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

(1) 14

(2) 13

(3) 6

(4) 9

Concept Questions :-

Standing waves
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Two pulses in a stretched string whose centres are initially 8 cm apart are moving towards each other as shown in the figure. The speed of each pulse is 2 cm/s. After 2 seconds, the total energy of the pulses will be

1. Zero

2. Purely kinetic

3. Purely potential

4. Partly kinetic and partly potential

Concept Questions :-

Energy of waves
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The diagram below shows the propagation of a wave. Which points are in the same phase : [AIIMS 1982]

(1) F, G

(2) C and E

(3) B and G

(4) B and F

Concept Questions :-

Wave motion
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The correct graph between the frequency n and square root of density (ρ) of wire, keeping its length, radius and tension constant, is :

(1)

(2)

(3)

(4)

Concept Questions :-

pressure wave in sound