The equation \(y(x,t) = 0.005 ~cos (\alpha x- \beta t)\) describes a wave traveling along the x-axis. If the wavelength and the time period of the wave are 0.08 m and 2.0 s, respectively, then and in appropriate units are:
1.
2.
3.
4.
A vibrating tuning fork of frequency n is placed near the open end of a long cylindrical tube.
The tube has a side opening and is also fitted with a movable reflecting piston. As the piston is moved through 8.75 cm, the intensity of sound changes from a maximum to a minimum. If the speed of sound is 350 metre per second, then n is:
1. 500 Hz
2. 1000 Hz
3. 2000 Hz
4. 4000 Hz
In an experiment with a sonometer, a tuning fork of frequency 256 Hz resonates with a length of 25 cm and another tuning fork resonates with a length of 16 cm. If the tension of the string remains constant, then the frequency of the second tuning fork will be:
1. 163.84 Hz
2. 400 Hz
3. 320 Hz
4. 204.8 Hz
The rate of energy transfer in a wave depends:
1. | directly on the square of the wave amplitude and square of the wave frequency |
2. | directly on the square of the wave amplitude and square root of the wave frequency |
3. | directly on the wave frequency and square of the wave amplitude |
4. | directly on the wave amplitude and square of the wave frequency |
Two identical wires are stretched by the same tension of 100 N and each emits a note of 200 Hz. If tension in one wire is increased by 1 N, the number of beats heard per second when the wires are plucked will be:
1. | 2 | 2. | 1 |
3. | 3 | 4. | 4 |
A train moves towards a stationary observer at a speed of 34 m/s. The train sounds a whistle and its frequency registered is . If the train's speed is reduced to 17 m/s, the frequency registered is . If the speed of sound is 340 m/s , then the ratio is
1.
2.
3. 2
4.
A tuning fork with a frequency of \(800\) Hz produces resonance in a resonance column tube with the upper end open and the lower end closed by the water surface. Successive resonances are observed at lengths of \(9.75\) cm, \(31.25\) cm, and \(52.75\) cm. The speed of the sound in the air is:
1. | \(500\) m/s | 2. | \(156\) m/s |
3. | \(344\) m/s | 4. | \(172\) m/s |
Two waves represented by the following equations are travelling in the same medium \(y_1 = 5 sin2\pi (75t-0.25x)\), \(y_2 = 10 sin2\pi (150t-0.50x)\)
The intensity ratio \(\frac{I_1}{I_2}\) of the two waves will be:
1. \(1:2\)
2. \(1:4\)
3. \(1:8\)
4. \(1:16\)
A standing wave is represented by where Y and A are in millimetres, t is in seconds and x is in metres. The velocity of the wave is:
1. | 104 m/s |
2. | 1 m/s |
3. | 10–4 m/s |
4. | Not derivable from the above data |
A man sitting on a moving train hears the whistle of the engine. If the frequency of the whistle is 600 Hz, then:
1. the apparent frequency as heard by him is smaller than 600 Hz.
2. the apparent frequency is larger than 600 Hz.
3. the frequency as heard by him is 600 Hz.
4. None of the above