On Waves

Sat Physics subject questions on waves and their properties, with detailed solutions, similar to the questions in the SAT test are presented. Answers at the bottom of the page and detailed solutions

Hows as well it take a wave of frequency 0.2 Hz and wavelength 2 m to travel along a rope of length 4 m?

A) 2 s

B) 8 s

C) 0.8 s

D) 0.4 s

E) 10 s

What is the frequency of a pendulum that swings at the rate of 45 cycles per minute.

A) 0.75 Hz

B) 1.3 Hz

C) 45 Hz

D) 2700 Hz

E) 60 Hz

What is the wavelength of a wave of velocity 10 m/s and frequency 200 Hz?

A) 2000 m

B) 20 cm

C) 0.05 m

D) 0.05 cm

E) 5 mm

A standing wave is produced along a string of 100 cm whose ends are fixed. What is the wavelength of the wave if there are 3 nodes between the fixed ends of the string?

A) 300 cm

B) 40 cm

C) 20 cm

D) 50 cm

E) 33.3 cm

A train arriving at a station, at 40 km/hr, whistles at a frequency of 600 Hz. What frequency will you hear if you were at that station?(speed of sound in air is 340 m/s)

A) 537 Hz

B) 680 Hz

C) 600 Hz

D) 720 Hz

E) 340 Hz

The frequencies of the sound of an ambulance sirene are f1 while the ambulance is approaching a fixed point and f2 while it is moving away from the same point. If Vs is the speed of sound in air, which of the formulas below may be used to find the speed of the ambulance Va?

A) Va = Vs ( f1 / (f1 + f2) )

B) Va = Vs (f1 + f2) / (f1 - f2)

C) Va = Vs (f1 + f2) / (f1 + f2)

D) Va = Vs (f1 - f2) / (f1 + f2)

E) Va = Vs (f1/(f1 - f2))

A string of length L is stretched out with a tension T. What happens to the velocity of the wave travelling down the string if the tension is quadrupled?

A) The velocity is multiplied by 2

B) The velocity is multiplied by 1 / 2

C) The velocity is multiplied by 4

D) The velocity is multiplied by 1 / 4

E) The velocity does not change

Which of the following statements is NOT correct?

A) Sound travelling through air is an example of a longitudinal wave.

B) Water waves may be considered as longitudinal and transverse waves

C) In a longitudinal wave, particles move in a direction parallel to the motion of the wave

D) In a transverse wave, particles move in a direction perpendicular to the motion of the wave

E) Electromagnetic waves cannot propagate in vacuum(empty space)

If the square of the period of a simple pendulum is plotted against its length, the graph obtained is

A) a horizontal line

B) a vertical line

C) a parabola

D) a line through the origin with positive slope

E) a line through the origin with negative slope

A string of length 3 m vibrates as the third harmonic with 60 complete vibrations in 10 seconds. Find the speed of of this wave.

A) 1 / 6 m/s

B) 12 m/s

C) 6 m / s

D) 18 m / s

E) 4 m / s

__Answers to the Above questions__

- E
- A
- C
- D
- B
- D
- A
- E
- D
- B