Which of the following waves CANNOT be polarised?
Ultrasonic waves
A horizontal string plucked vertically in the middle
Ultraviolet radiation
Radio waves
What determines "loudness" of a musical note?
An open pipe of length L is resonating at its fundamental frequency. Which statement is correct?
A small vibrating object on the surface of a ripple tank produces waves of frequency 20 Hz and speed 60 cm/s. If the source S is moving to the right as shown the figure, with a speed of 20 cm/s.
What frequency would an observer at point C hear?
60 Hz.
6.7 Hz.
30 Hz.
13.3 Hz.
The fundamental note produced by a closed pipe in a piano is 128 Hz.
What is the wavelength of its first overtone?
2.01 m.
0.72 m.
0.52 m.
7.2 m.
