Question:
A tuning fork A of unknown frequency produces 5 beats/s with a fork of known frequency $340 \mathrm{~Hz}$. When fork $\mathrm{A}$ is filed, the beat frequency decreases to 2 beats/s. What is the frequency of fork A ?
$342 \mathrm{~Hz}$
$345 \mathrm{~Hz}$
$335 \mathrm{~Hz}$
$338 \mathrm{~Hz}$
Correct Option: , 3
Solution:
Initially beat frequency $=5 \mathrm{~Hz}$
so, $\rho_{\mathrm{A}}=340 \pm 5=345 \mathrm{~Hz}$, or $335 \mathrm{~Hz}$
after filing frequency increases slightly
so, new value of frequency of $\mathrm{A}>\rho_{\mathrm{A}}$
Now, beat frequency $=2 \mathrm{~Hz}$
$\Rightarrow$ new $\rho_{\mathrm{A}}=340 \pm 2=342 \mathrm{~Hz}$, or $338 \mathrm{~Hz}$
hence, original frequency of $\mathrm{A}$ is $\rho_{\mathrm{A}}=335 \mathrm{~Hz}$
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- JEE Main
- Exam Pattern
- Previous Year Papers
- PYQ Chapterwise
- Physics
- Kinematics 1D
- Kinemetics 2D
- Friction
- Work, Power, Energy
- Centre of Mass and Collision
- Rotational Dynamics
- Gravitation
- Calorimetry
- Elasticity
- Thermal Expansion
- Heat Transfer
- Kinetic Theory of Gases
- Thermodynamics
- Simple Harmonic Motion
- Wave on String
- Sound waves
- Fluid Mechanics
- Electrostatics
- Current Electricity
- Capacitor
- Magnetism and Matter
- Electromagnetic Induction
- Atomic Structure
- Dual Nature of Matter
- Nuclear Physics
- Radioactivity
- Semiconductors
- Communication System
- Error in Measurement & instruments
- Alternating Current
- Electromagnetic Waves
- Wave Optics
- X-Rays
- All Subjects
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- Motion in a Plane
- Law of Motion
- Work, Energy and Power
- Systems of Particles and Rotational Motion
- Gravitation
- Mechanical Properties of Solids
- Mechanical Properties of Fluids
- Thermal Properties of matter
- Thermodynamics
- Kinetic Theory
- Oscillations
- Waves
- Electric Charge and Fields
- Electrostatic Potential and Capacitance
- Current Electricity
- Thermoelectric Effects of Electric Current
- Heating Effects of Electric Current
- Moving Charges and Magnetism
- Magnetism and Matter
- Electromagnetic Induction
- Alternating Current
- Electromagnetic Wave
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