COMEDK · Physics · 16. Waves and Sound
With what velocity should an observer approach a stationary sound source, so that the apparent frequency of sound should appear double the actual frequency?
- A \(2 v\)
- B \(v\)
- C \(v / 2\)
- D \(3 v\)
Answer & Solution
Correct Answer
(B) \(v\)
Step-by-step Solution
Detailed explanation
The apparent frequency \(f'\) heard by an observer moving towards a stationary source is given by the Doppler effect formula: \(f' = f \left( \dfrac{v + v_o}{v} \right)\) where \(f\) is the actual frequency, \(v\) is the speed of sound, and \(v_o\) is the velocity of the…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- A wire of \(24 \Omega\) resistance is bent to form a square loop. A 10 V battery negligible internal resistance is connected across the diagonals of the square loop. The potential drop across one of its sides is:COMEDK 2025 Medium
- A transformer which steps down \(330 \mathrm{~V}\) to \(33 \mathrm{~V}\) is to operate a device having impedance \(110 \Omega\). The current drawn by the primary coil of the transformer is :COMEDK 2024 Medium
- A convex lens forms a real image of an object with magnification \(m_1\). The lens is moved towards the object to obtain another real image of magnification \(\mathrm{m}_2\). The image distance is increased by x . The focal length of the lens isCOMEDK 2025 Medium
- A student unable to answer a question on Newton's laws of motion attempts to pull himself up by tugging on his hair. Me will not succeedCOMEDK 2017 Medium
- A light rod of length 1 m is suspended from ceiling horizontally by means of two vertical wires of equal length tied to its ends. One of the wires is made of material X and is of cross-section \(0.1\ \text{cm}^2\) and the other of material Y of cross-section \(0.3\ \text{cm}^2\). A weight is hung from the wire at a point to produce equal strain in the wires. The ratio of Young's moduli of wires A to B is 3:1. The location of the point from one end of the wire isCOMEDK 2026 Medium
- Point charge \(\sqrt{2}C, \sqrt{2}C\), and \(-2C\) are placed at the three vertices of a right-angled triangle in air. [as shown in the figure below] What is the electric field at a point P on the hypotenuse that is equidistant from all three charges. Given distances \(XP = YP = ZP = 0.5\ m\)
COMEDK 2026 Medium
More PYQs from COMEDK
- A Si and a Ge diode has identical physical dimensions. The band gap in Si is larger than that in Ge. On applying identical reverse bias across these diodes,COMEDK 2025 Easy
- An electric field and magnetic field \(1.8 \times 10^4\ Vm^{-1}\) and \(6 \times 10^{-3}\ T\) respectively are applied simultaneously on an electron beam such that path of the beam remains undeviated, then the speed of the electron will be:COMEDK 2026 Easy
- A cylinder of radius \(r\) and of thermal conductivity \(K_1\) is surrounded by a cylindrical shell of inner radius \(r\) and outer radius \(2 r\) made of a material of thermal conductivity \(K_2\). The effective thermal conductivity of the system isCOMEDK 2023 Medium
- Three equal charges are placed on the three corners of a square. If the force between \(q_1\) and \(q_2\) is \(F_{12}\) and that between \(q_1\) and \(q_3\) is \(F_{13}\), then the ratio of magnitudes \(\left(\frac{F_{13}}{F_{12}}\right)\) isCOMEDK 2024 Medium
- The value of \(\lim\limits_{x \to 3}\left[\dfrac{1}{x-3} + \dfrac{9x}{27-x^3}\right]\) is:COMEDK 2026 Medium
- Point charges \(-3 \mathrm{Q},-\mathrm{q}, 2 \mathrm{q}\) and 2 Q are placed, one at each corner of a square. The relation between Q and q for which the potential at the centre of the square is zero isCOMEDK 2025 Easy