Which one of the following statements is true?
1. | Both light and sound waves in the air are transverse. |
2. | The sound waves in the air are longitudinal while the light waves are transverse. |
3. | Both light and sound waves in the air are longitudinal. |
4. | Both light and sound waves can travel in a vacuum. |
A transverse wave propagating along the x-axis is represented by:
\(y=(x,t)=8.0\mathrm{sin}(0.5\pi x-4\pi t-\frac{\pi}{4})\) where \(x\) is in meters and \(t\) in seconds. The speed of the wave is:
1. \(4\pi\) m/s
2. \(0.5\) m/s
3. \(\frac{\pi}{4}\) m/s
4. \(8\) m/s
Two sound waves with wavelengths 5.0 m and 5.5 m, respectively, propagate in gas with a velocity of 330 m/s. How many beats per second can we expect?
1. 12
2. 0
3. 1
4. 6
The wave described by \(y=0.25\sin (10\pi x-2\pi t)\), where \(x \) and \(y\) are in metre and \(t\) in second, is a wave travelling along the:
1. | \(1\) Hz | –ve x-direction with frequency
2. | \(\pi\) Hz and wavelength \(\lambda=0.2\) m | +ve x-direction with frequency
3. | \(1\) Hz and wavelength \(\lambda=0.2\) m | +ve x-direction with frequency
4. | \(0.25\) m and wavelength \(\lambda=0.2\) m | –ve x-direction with amplitude
Each of the two strings of lengths 51.6 cm and 49.1 cm is tensioned separately by 20 N of force. The mass per unit length of both strings is the same and equals 1 g/m. When both the strings vibrate simultaneously, the number of beats is:
1. | 5 | 2. | 7 |
3. | 8 | 4. | 3 |
A wave in a string has an amplitude of 2 cm. The wave travels in the positive direction of the x-axis with a speed of 128 m/s and it is noted that 5 complete waves fit in the 4 m length of the string. The equation describing the wave is:
1. | y = (0.02)m sin(7.85x+1005t) |
2. | y = (0.02)m sin(15.7x -2010t) |
3. | y = (0.02)m sin(15.7x+2010t) |
4. | y = (0.02)m sin(7.85x -1005t) |
A tuning fork of frequency \(512\) Hz makes \(4\) beats/s with the vibrating string of a piano. The beat frequency decreases to \(2\) beats/s when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was:
1. \(510\) Hz
2. \(514\) Hz
3. \(516\) Hz
4. \(508\) Hz
A transverse wave is represented by y = Asin(ωt -kx). At what value of the wavelength is the wave velocity equal to the maximum particle velocity?
1. A/2
2. A
3. 2A
4. A
Sound waves travel at \(350\) m/s through warm air and at \(3500\) m/s through brass. The wavelength of a \(700\) Hz acoustic wave as it enters brass from warm air:
1. | increase by a factor of \(20\) |
2. | increase by a factor of \(10\) |
3. | decrease by a factor of \(20\) |
4. | decrease by a factor of \(10\) |
Two waves are represented by the equations and
,
where \(x\) is in metres and \(t\) in seconds. The phase difference between them is:
1. \(1.25\) rad
2. \(1.57\) rad
3. \(0.57\) rad
4. \(1.0\) rad