JEE Mains · Physics · STD 11 - 14. waves and sound
The frequency of a car horn encountered a change from \(400\, {Hz}\) to \(500\, {Hz}\), when the car approaches a vertical wall. If the speed of sound is \(330\, {m} / {s}\). Then the speed of car is \(.....\,{km} / {h} .\)
- A \(330\)
- B \(132\)
- C \(185\)
- D \(852\)
Answer & Solution
Correct Answer
(B) \(132\)
Step-by-step Solution
Detailed explanation
Wall as an observer Frequency received by wall \({f}_{1}={f}_{0}\left(\frac{{C}}{{C}-{V}}\right)\) Again wall as a source Frequency received by observer on car \({f}_{2}={f}_{1}\left(\frac{{C}+{V}}{{C}}\right)\) \(500=400\left(\frac{{C}+{v}}{{C}-{V}}\right)\)…
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
- An electron with energy \(0.1\,ke\,V\) moves at right angle to the earth's magnetic field of \(1 \times 10^{-4}\,Wbm ^{-2}\). The frequency of revolution of the electron will be. (Take mass of electron \(=9.0 \times 10^{-31}\,kg\) )JEE Mains 2022 Easy
- A parallel beam of monochromatic light of wavelength \(600 \mathrm{~nm}\) passes through single slit of \(0.4 \mathrm{~mm}\) width. Angular divergence corresponding to second order minima would be _______ \(\times 10^{-3} \mathrm{rad}\).JEE Mains 2024 Hard
- The angular momentum of an electron in a hydrogen atom is proportional to _______. (Where \(\mathrm{r}\) is the radius of orbit of electron)JEE Mains 2024 Hard
- Match List-\(I\) with List-\(II\) Choose the correct answer from the options given below :
JEE Mains 2024 Hard - An \(NPN\) transistor is used in common emitter configuration as an amplifier with \(1\,k\Omega \) load resistance. Signal voltage of \(10\,mV\) is applied across the base emitter. This produces a \(3\,mA\) change in the collector current and \(15\,\mu A\) change in the base current of the amplifier. The input resistance and voltage gain areJEE Mains 2019 Hard
- \(\gamma_{\mathrm{A}}\) is the specific heat ratio of monoatomic gas A having 3 translational degrees of freedom. \(\gamma_B\) is the specific heat ratio of polyatomic gas B having 3 translational, 3 rotational degrees of freedom and 1 vibrational mode. If \(\frac{\gamma_{\mathrm{A}}}{\gamma_{\mathrm{B}}}=\left(1+\frac{1}{\mathrm{n}}\right)\), then the value of \(n\) is _______.JEE Mains 2025 Easy
More PYQs from JEE Mains
- The differential equation representing the family of ellipse having foci either on the \(x-\) axis or on the \(y-\) axis centre at the origin and passing through the point \((0,3)\) isJEE Mains 2018 Hard
- A beam of protons with speed \(4 \times 10^{5}\, ms ^{-1}\) enters a uniform magnetic field of \(0.3\, T\) at an angle of \(60^{\circ}\) to the magnetic field. The pitch of the resulting helical path of protons is close to....\(cm\) (Mass of the proton \(=1.67 \times 10^{-27}\, kg\), charge of the proton \(=1.69 \times 10^{-19}\,C\))JEE Mains 2020 Medium
- Two identical bodies, projected with the same speed at two different angles cover the same horizontal range \(R\). If the time of flight of these bodies are \(5\) s and \(10\) s, respectively, then the value of \(R\) is ________ m. (Take \(g=10\) m/s\(^2\))JEE Mains 2026 Medium
- All possible values of \(\theta \in[0,2 \pi]\) for which \(\sin 2 \theta+\tan 2 \theta>0\) lie inJEE Mains 2021 Hard
- A car is standing \(200\, m\) behind a bus, which is also at rest. The two start moving at the same instant but with different forward accelerations. The bus has acceleration \(2\,m/s^2\) and the car has acceleration \(4\, m/s^2\) . The car will catch up with the bus after a time ofJEE Mains 2017 Hard
- Let \(\lambda \) be a real number for which the system of linear equations \(x + y + z = 6\)
; \(4x + \lambda y - \lambda z = \lambda - 2\) ; \(3x + 2y -4z = -5\) Has indefinitely many solutions. Then \(\lambda \) is a root of the quadratic equationJEE Mains 2019 Hard