Units and Measurements
Motion in a Plane
Laws of Motion
- Introduction to Laws of Motion
- Aristotle’s Fallacy
- Newton’s Laws of Motion
- Inertial and Non-inertial Frames of Reference
- Types of Forces
- Work Energy Theorem
- Principle of Conservation of Linear Momentum
- Impulse of Force
- Rotational Analogue of a Force - Moment of a Force Or Torque
- Couple and Its Torque
- Mechanical Equilibrium
- Centre of Mass
- Centre of Gravity
- Introduction to Gravitation
- Kepler’s Laws
- Newton’s Universal Law of Gravitation
- Measurement of the Gravitational Constant (G)
- Acceleration Due to Gravity (Earth’s Gravitational Acceleration)
- Variation in the Acceleration Due to Gravity with Altitude, Depth, Latitude and Shape
- Gravitational Potential and Potential Energy
- Earth Satellites
Mechanical Properties of Solids
Thermal Properties of Matter
Electric Current Through Conductors
- Electric Current
- Flow of Current Through a Conductor
- Drift Speed
- Ohm's Law (V = IR)
- Limitations of Ohm’s Law
- Electrical Power
- Specific Resistance (Resistivity)
- Variation of Resistance with Temperature
- Electromotive Force (emf)
- Combination of Cells in Series and in Parallel
- Types of Cells
- Combination of Resistors - Series and Parallel
Electromagnetic Waves and Communication System
- Musical Sound
- Source Moving and Listener Stationary
- Listener Approaching a Stationary Source with Velocity vL
- Both Source and Listener are Moving
- Common Properties between Doppler Effect of Sound and Light
- Major Differences between Doppler Effects of Sound and Light
- Effect of wind velocity on Doppler's effect in sound
- Applications of Doppler's effect
Related QuestionsVIEW ALL 
In discussing Doppler effect, we use the word "apparent frequency". Does it mean that the frequency of the sound is still that of the source and it is some physiological phenomenon in the listener's ear that gives rise to Doppler effect? Think for the observer approaching the source and for the source approaching the observer.
A narrow sound pulse (for example, a short pip by a whistle) is sent across a medium. (a) Does the pulse have a definite (i) frequency, (ii) wavelength, (iii) speed of propagation? (b) If the pulse rate is 1 after every 20 s, (that is the whistle is blown for a split of second after every 20 s), is the frequency of the note produced by the whistle equal to 1/20 or 0.05 Hz
A train whistling at constant frequency is moving towards a station at a constant speed V. The train goes past a stationary observer on the station. The frequency n ′ of the sound as heard by the observer is plotted as a function of time t (figure). Identify the expected curve.
A train, standing in a station yard, blows a whistle of frequency 400 Hz in still air. The wind starts blowing in the direction from the yard to the station with a speed of 10 m/s. Given that the speed of sound in still air is 340 m/s ______.
- the frequency of sound as heard by an observer standing on the platform is 400 Hz.
- the speed of sound for the observer standing on the platform is 350 m/s.
- the frequency of sound as heard by the observer standing on the platform will increase.
- the frequency of sound as heard by the observer standing on the platform will decrease.
A sitar wire is replaced by another wire of same length and material but of three times the earlier radius. If the tension in the wire remains the same, by what factor will the frequency change?