- 1(current)
Q. No.A stone dropped from the top of a tower of height \(300\) m splashes into the water of a pond near the base of the tower. When is the splash heard at the top?
(Given that the speed of sound in air is \(340\) m/s and \(g=9.8\) m/s2)
1. \(7.7\)
2. \(8.7\)
3. \(6.7\)
4. \(7.8\)
The speed of sound in air is:
| 1. | dependent on pressure. |
| 2. | decreases with temperature. |
| 3. | independent of temperature. |
| 4. | increases with humidity. |
A bat emits an ultrasonic sound of frequency 1000 kHz in the air. If the sound meets a water surface, what is the wavelength of the reflected sound? (The speed of sound in air is 340 m/sec and in water is 1486 m/sec)
1. \(3.4 \times 10^{-4}~\text{m}\)
2. \(1 . 49 \times 10^{- 3} ~ \text{m}\)
3. \(2 . 34 \times 10^{- 2} ~\text{m}\)
4. \(1 . 73 \times10^{- 3} ~\text{m}\)
A bat emits an ultrasonic sound of frequency \(1000~\text{kHz}\) in the air. If the sound meets a water surface, what is the wavelength of the refracted sound?
(speed of sound in air is \(340~\mathrm{m/s}\) and in water \(1486~\mathrm{m/s}\))
| 1. | \(3.4 \times 10^{-4} \mathrm{~m} \) | 2. | \(1.4 \times 10^{-3} \mathrm{~m} \) |
| 3. | \(2.5 \times 10^{-4} \mathrm{~m} \) | 4. | \(1.8 \times 10^{-3} \mathrm{~m}\) |
A hospital uses an ultrasonic scanner to locate tumors in a tissue. What is the wavelength of sound in the tissue in which the speed of sound is \(1.7~\text{km/s}\)? The operating frequency of the scanner is \(4.2~\text{MHz}\).
1. \(3.0 \times10^{-4}~\text{m}\)
2. \(4.0 \times10^{-4}~\text{m}\)
3. \(3.5 \times10^{-4}~\text{m}\)
4. \(2.0 \times10^{-4}~\text{m}\)
\(y(x,t)=0.06\sin\Big(\frac{2\pi}{3}x\Big)\cos(120\pi t)\)
where \(x\) and \(y\) are in metre and \(t\) in second. The length of the string is \(1.5\) m and its mass is \(3\times10^{-2}\) kg. The tension in the string is:
1. \(540\) N
2. \(648\) N
3. \(200\) N
4. \(425\) N
A train, standing in a station yard, blows a whistle of frequency 400 Hz in still air. The wind starts blowing in the direction from the yard to the station with a speed of 10 m/sec. What is the speed of sound for an observer standing on the station’s platform?
1. 332 m/s
2. 360 m/s
3. 344 m/s
4. 350 m/s
Earthquakes generate sound waves inside the earth. Unlike a gas, the earth can experience both transverse (S) and longitudinal (P) sound waves. Typically the speed of the S wave is about 4.0 km/s, and that of the P waves is 8.0 km/s. A seismograph records P and S waves from an earthquake. The first P wave arrives 4 min before the first S wave. Assuming the waves travel in a straight line, at what distance does the earthquake occur?
1. 1854 km
2. 2320 km
3. 1920 km
4. 2000 km
- 1(current)
Q. No.
© 2024 GoodEd Technologies Pvt. Ltd.