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Question #42129

Difficulty: 8/10 | 🟢 Free

The Question

A damped harmonic oscillator of mass m=0.2 kgm = 0.2\text{ kg} is submerged in a viscous fluid. The damping force is given by Fd=−bvF_d = -b v, where the damping coefficient bb depends on the absolute temperature TT (in Kelvin) of the fluid as b=αTb = \alpha T, with α=4×10−3 kg s−1 K−1\alpha = 4 \times 10^{-3}\text{ kg s}^{-1}\text{ K}^{-1}. The temperature of the fluid is measured using a faulty linear thermometer scale ∘X^\circ X. On this scale, the freezing point of water is 20∘X20^\circ X and the boiling point of water is 120∘X120^\circ X (at standard atmospheric pressure). During the experiment, the faulty thermometer reads 47∘X47^\circ X, and the damped angular frequency of the oscillator is measured to be ωd=4 rad s−1\omega_d = 4\text{ rad s}^{-1}. What is the undamped natural angular frequency ω0\omega_0 of the oscillator?

Options

  • A.

    5 \text{ rad s}^{-1}

  • B.

    7 rad s−1\sqrt{7} \text{ rad s}^{-1}

  • C.

    213 rad s−12\sqrt{13} \text{ rad s}^{-1}

  • D.

    17.44 rad s−1\sqrt{17.44} \text{ rad s}^{-1}

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Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Intuition_Breaker

Train your brain to resist "obvious" answers that are designed to deceive your intuition.

Concepts Behind This Question

Celsius-Fahrenheit Calibration Errors|Damped Oscillation Equation

Why This Question Is Tricky

Common Mistakes

This question tests the synthesis of linear thermometry calibration with the mechanics of damped harmonic oscillation.

A primary trap is failing to convert the calibrated temperature to absolute Kelvin before substituting it into the temperature-dependent damping equation, which violates the principle of homogeneity.

Additionally, students frequently misremember the decay constant as λ=b/m\lambda = b/m instead of b/2mb/2m (leading to Option C), or apply the wrong sign in the damped frequency relation by assuming ω02=ωd2−λ2\omega_0^2 = \omega_d^2 - \lambda^2 (leading to Option B).

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Question Information

SubjectPhysics
ChapterThermal Properties of Matter - Class 11 Part 2
ConceptCelsius-Fahrenheit Calibration Errors
Difficulty8
Cognitive Load7
Target Solve Time160 sec
AccessFree