Which one among the following is true for the speed of sound in a given medium ?
- A.Speed of sound remains same at all frequencies
- B.Speed of sound is faster at higher frequencies
- C.Speed of sound is slower at higher frequencies
- D.Speed of sound is slower at higher wavelengths
Correct answer
Explanation
The correct answer is A, Speed of sound remains same at all frequencies. In a given medium under the same conditions, sounds of all frequencies travel at the same speed; the speed depends on the medium, not on the pitch.
The speed of sound is set by the properties of the medium: its elasticity, its density and, for a gas, its temperature and humidity. In dry air at 0 °C it is about 332 m/s, rising to about 343 m/s at 20 °C; it is about 1,500 m/s in water and over 5,000 m/s in steel. Since v = fλ and v is fixed, a higher frequency simply means a shorter wavelength. That is why, at a concert, the high notes and the low notes reach a listener at the back of the hall together.
B is wrong: high-frequency sound does not travel faster in a given medium. C is wrong: high-frequency sound does not travel slower either; its wavelength is shorter. D is wrong: longer wavelengths are not slower; speed stays the same while wavelength and frequency change in opposite directions.
Exam tip: v = fλ; in one medium v is constant, so frequency up means wavelength down; v rises with temperature and is highest in solids.
Practice Questions
View allThe fact that the planets move around the Sun, not in circles but in ellipses, was first demonstrated by
- A.Galileo
- B.Martin Luther
- C.Johannes Kepler
- D.Copernicus
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In 1609 Kepler showed that the planets move around the Sun in elliptical orbits, with the Sun at one focus of the ellipse.
Read the full explanation →Which one of the following statements is correct?
- A.Urea is produced in liver.
- B.Urea is produced in blood.
- C.Urea is produced from digestion of starch.
- D.Urea is produced in lung and kidney.
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Liver cells turn the toxic ammonia released from the breakdown of amino acids into urea through the ornithine cycle, also called the urea cycle.
Read the full explanation →Which one of the following is the correct sequence of passage of light in a compound microscope?
- A.Condenser-Objective lens-Eyepiece-Body tube
- B.Objective lens-Condenser-Body tube-Eyepiece
- C.Condenser-Objective lens-Body tube-Eyepiece
- D.Eyepiece-Objective lens-Body tube-Mirror
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Light passes through the condenser to the specimen, is picked up by the objective lens, travels up the body tube and reaches the eye through the eyepiece.
Read the full explanation →Which one of the following statements regarding haemoglobin is correct?
- A.Haemoglobin present in RBC can carry only oxygen but not carbon dioxide.
- B.Haemoglobin of RBC can carry both oxygen and carbon dioxide.
- C.Haemoglobin of RBC can carry only carbon dioxide.
- D.Haemoglobin is only used for blood clotting and not for carrying gases.
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Read the full explanation →Which one of the following statements regarding histone proteins is correct?
- A.Histones are proteins that are present in mitochondrial membrane.
- B.Histones are proteins that are present in nucleus in association with DNA.
- C.Histones are proteins associated with lipids in the cytosol.
- D.Histones are proteins associated with carbohydrates in the cytosol.
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They are the proteins around which DNA winds to form chromatin in the nucleus of eukaryotic cells. Histones are small basic proteins, rich in the positively charged amino acids lysine and arginine, which attract the negatively charged phosphate groups of DNA.
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