If the amplitude of waves at distance r from a point source is A, the amplitude at a distance 2r will be :

(1) 2A

(2) A

(3) A/2

(4) A/4

A wave is reflected from a rigid support. The change in phase on reflection will be : 

(1) π/4

(2) π/2

(3) π

(4) 2π

A plane wave is represented by $x=1.2\sin (314t+12.56y)$

Where x and y are distances measured along in x and y direction in meters and t is time in seconds. This wave has 

(1) A wavelength of 0.25 m and travels in + ve x-direction

(2) A wavelength of 0.25 m and travels in + ve y-direction

(3) A wavelength of 0.5 m and travels in – ve y-direction

(4) A wavelength of 0.5 m and travels in – ve x-direction

The equation of a wave traveling in a string can be written as $y=3\cos \pi (100t-x)$. Its wavelength is :

(1) 100 cm

(2) 2 cm

(3) 5 cm

(4) None of the above

A transverse wave is described by the equation $y=Y_0\sin \left(2\mathrm{\pi ft}-\frac{2\mathrm{\pi }}{\mathrm{\lambda }}\mathrm{x}\right)$. The maximum particle velocity is four times the wave velocity if :

(1) $\lambda =\frac{\pi Y_0}{4}$

(2) $\lambda =\frac{\pi Y_0}{2}$

(3) $\lambda =\pi Y_0$

(4) $\lambda =2\pi Y_0$

A transverse wave of amplitude 0.5 m and wavelength 1 m and frequency 2 Hz is propagating in a string in the negative x-direction. The expression for this wave is :

(1) $y(x,t)=0.5\sin (2\pi x-4\pi t)$

(2) $y(x,t)=0.5\cos (2\pi x+4\pi t)$

(3) $y(x,t)=0.5\sin (\pi x-2\pi t)$

(4) $y(x,t)=0.5\cos (2\pi x+2\pi t)$

Which one of the following does not represent a traveling wave :

1. $y=\sin (x-vt)$

2. $y=y_m\sin k(x+vt)$

3. $y=y_m\sin (x-vt)$

4. $y=f(x^2-v{t}^2)$

A transverse wave is represented by the equation $y=y_0\sin \frac{2\pi }{\lambda }(vt-x)$

For what value of λ, the maximum particle velocity equal to two times the wave velocity?

(1) $\lambda =2\pi y_0$

(2) $\lambda =\pi y_0/3$

(3) $\lambda =\pi y_0/2$

(4) $\lambda =\pi y_0$