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Question #1
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A wave of frequency 500 Hz has speed 350 m/s. Wavelength is
Question #2
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Which thermodynamic process occurs at a constant volume?
Correct Answer: Option C
Explanation:
An isochoric process is a thermodynamic process in which the volume of the closed system remains constant (delta V = 0). Because there is no change in volume, the system does zero pressure-volume work (W = Pdelta V = 0). According to the first law of thermodynamics, any heat added goes entirely into increasing the internal energy. Isobaric is constant pressure; isothermal is constant temperature.
An isochoric process is a thermodynamic process in which the volume of the closed system remains constant (delta V = 0). Because there is no change in volume, the system does zero pressure-volume work (W = Pdelta V = 0). According to the first law of thermodynamics, any heat added goes entirely into increasing the internal energy. Isobaric is constant pressure; isothermal is constant temperature.
Question #3
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Linear expansion coefficient α = 2×10⁻⁵/°C. Length increase for 1 m rod heated 50°C:
Correct Answer: Option A
Explanation:
ΔL = L₀αΔT = 1×2×10⁻⁵×50 = 100×10⁻⁵ = 10⁻³ m = 1 mm. Direct expansion formula application. Memory tip: 'ΔL = LαΔT; convert result to required units'. Tests thermal expansion calculation with unit conversion, frequently appearing in competitive exams.
ΔL = L₀αΔT = 1×2×10⁻⁵×50 = 100×10⁻⁵ = 10⁻³ m = 1 mm. Direct expansion formula application. Memory tip: 'ΔL = LαΔT; convert result to required units'. Tests thermal expansion calculation with unit conversion, frequently appearing in competitive exams.
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