Three sound waves of equal amplitudes have frequencies $(f-1 ), f, (f+ 1)$. They superpose to give beats. The number of beats produced per second will be:
$4$
$3$
$2$
$1$
Figure shows the wave $y = A\,sin\,(\omega t -kx)$ .What is the magnitude of slope of the curved at $B$
A train is moving towards a stationary observer. Which of the following curve best represents the frequency received by observer $f$ as a function of time ?
Beats are produced by two waves $y_1 = a\, sin\, (1000\, \pi t)$ and $y^2 = a\, sin\, (998\, \pi t)$ The number of beats heard per second is
Fundamental frequency of a sonometer wire is $n$ . If the length and diameter of the wire are doubled keeping the tension same, then the new fundamental frequency is
A source of sound is travelling with a velocity of $40\,km/hour$ towards an observer and emits sound of frequency $2000\,Hz$ . If the velocity of sound is $1220\,km/hour$ , what is the apparent frequency heard by the observer ..... $Hz$