List of top Physics Questions on doppler effect asked in MHT CET

A train moving at 20 m/s approaches a stationary observer. The frequency of the whistle emitted by the train is 640 Hz. If the velocity of sound is 340 m/s, the apparent frequency heard by the observer is:
A train moving at 20 m/s approaches a stationary observer. The frequency of the whistle emitted by the train is 640 Hz. If the velocity of sound is 340 m/s, the apparent frequency heard by the observer is:
Calculate the percentage increase in apparent frequency for an observer moving towards a stationary sound source with \( \frac{1}{5} \)th the velocity of sound.
A person observes two moving trains. First reaching the station and another leaves the station with equal speed of \(30 \text{ m/s}\). If both trains emit sounds of frequency \(300 \text{ Hz}\), difference of frequencies heard by the person will be (speed of sound in air \(330 \text{ m/s}\))
When an observer moves towards a stationary source with velocity '\(V_1\)', the apparent frequency of emitted note is '\(F_1\)'. When observer moves away from stationary source with velocity '\(V_1\)' the apparent frequency is '\(F_2\)'. If '\(v\)' is velocity of sound in air and \(\frac{F_1}{F_2} = 2\), then \(\frac{v}{V_1}\) is equal to
A person observes two moving trains. First reaching the station and another leaves the station with equal speed of \(30 \text{ m/s}\). If both trains emit sounds of frequency \(300 \text{ Hz}\), difference of frequencies heard by the person will be (speed of sound in air \(330 \text{ m/s}\))
A person observes two moving trains. First reaching the station and another leaves the station with equal speed of \(30 \text{ m/s}\). If both trains emit sounds of frequency \(300 \text{ Hz}\), difference of frequencies heard by the person will be (speed of sound in air \(330 \text{ m/s}\))
A passenger is sitting in a fast moving train. The engine of the train blows a whistle of frequency N. If the apparent frequency of sound heard by the passengers is \( N' \), then:
The pitch of whistle of an engine appears to drop by 30% of the original value when it passes a stationary observer. If speed of sound in air is \(350\text{ m/s}\), then the speed of engine in \(\text{m/s}\) is
Two sounding sources send waves at certain temperature in air of wavelength \( 60 \text{ cm} \) and \( 60.6 \text{ cm} \) respectively. The frequency of sources differ by \( 5 \text{ Hz} \). The velocity of sound in air at same temperature is
A source of sound is moving towards a stationary observer with $\left(\frac{1}{10}\right)^{\text{th}}$ the speed of sound. The ratio of apparent to real frequency is
When both source and listener are approaching each other the observed frequency of sound is given by ($V_L$ and $V_S$ is the velocity of listener and source respectively, $n_0 = \text{radiated frequency}$)
The pitch of whistle of an engine appears to drop by 30% of the original value when it passes a stationary observer. If speed of sound in air is \(350\text{ m/s}\), then the speed of engine in \(\text{m/s}\) is