Waves Test - 67...

Two sine waves travel in the same direction in a medium. The amplitude of each wave is A and the phase difference between the two waves is $$120^{\circ}$$. The resultant amplitude will be

Two point lie on a ray are emerging from a source of simple harmonic wave having period $$0.045$$. The wave speed is $$300\ m/s$$ and points are at $$10\ m$$ and $$16\ m$$ from the source. They differ in phase by :

A simple harmonic wavetrain of amplitude $$5\ cm$$ and frequency $$100\ Hz$$ is travelling in the positive $$x-$$ direction with a velocity of $$30\ m/s$$. The displacement velocity and acceleration at $$t=3s$$ of a particle of the medium situated $$100\ cm$$ from the origin are respectively.

Two identical pulses move in opposite directions with same uniform speeds on a stretched string. The width and kinetic energy of each pulse is $$L$$ and $$k$$ respectively. At the instant they completely overlap, the kinetic energy of the width $$L$$ of the string where they overlap is:

A wave motion has the function $$Y=a_{0}\sin (\omega t-kx)$$. The graph in the figure shows how the displacement $$y$$ at a fixed point varies with time $$t$$. Which one of the labeled points shows a displacement equal to that at the position $$x=\pi/2k$$ at time $$t=0$$

A simple harmonic plane wave propagates along x-axis in a medium. The displacement of the particles as a function of time is shown in figure, for $$x = 0$$ (curve 1) and $$x = 7$$ (curve 2).
The two particles are within a span of one wavelength.
The speed of the wave is

Two separated sources emit sinusoidal travelling waves but have the same wavelength $$ \lambda $$ and are in phase at their respective sources. One travels a distance $$ l_{1} $$ to get to the observation point while the other travels a distance $$ l_{2} $$. The amplitude is minimum at the observation point, if $$ l_{1}-l_{2} $$ is an

Two vibration strings of the same material but lengths L and 2L have radii 2r and r, respectively. The are stretched  under the same tension. Both the strings vibrate in their fundamental modes, the one of length L with frequency $$n_1$$ and the other with frequency $$n_2$$. The ratio $$n_1/n_2$$ is given by 

Figure 5.55 shows a student setting up wave on a long stretched string. The student's hand makes one complete up and down movement in $$0.4 \,s$$ and in each up and down movement the hand moves by a height of $$0.3 \,m.$$ The wavelength of the waves on the string is $$0.8 \,m.$$
The amplitude of the wave is

Four pieces of string each of length L are joined end to end to make a long string of length $$4L.$$ The linear mass density of the strings are $$\mu, 4\mu, 9\mu$$ and $$16\mu,$$ respectively. One end of the combined string is tied to a fixed support and a transverse wave has been generated at the other end having frequency $$f$$ (ignore any reflection and absorptions). String has been stretched under a tension $$F.$$
Find the ratio of wavelengths of the waves on four strings, starting from right hand side.