Science
MediumQ. No. what-is-the-formula-for-heat-absorbed-by-a-substance
What is the formula for heat absorbed by a substance?
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AQ = mcθ
BQ = mc²
CQ = mθ/c
DQ = c/mθ
Correct Answer: Q = mcθYour Answer: A
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The formula for heat absorbed or released by a substance is a fundamental equation in thermodynamics. Option A (Q = mcθ) is CORRECT — this is the correct formula where Q is the heat energy absorbed or released (in joules or calories), m is the mass of the substance (in kg or grams), c is the specific heat capacity of the substance (in J/kg·K or cal/g·°C), and θ (theta) is the change in temperature. This formula tells us that the heat absorbed depends on three factors: mass, specific heat, and temperature change. It is the basis of calorimetry. Option B (Q = mc²) is incorrect — this is Einstein's mass-energy equivalence formula (E = mc²) where c represents the speed of light (3 × 10⁸ m/s). It has no relation to heat absorbed by a substance in calorimetry. Option C (Q = mθ/c) is incorrect — dividing temperature change by specific heat gives the wrong relationship. In the correct formula, specific heat is multiplied (Q = mcθ), not divided. Option D (Q = c/mθ) is incorrect — this inverted formula has no physical meaning in thermodynamics. For exams: Q = mcθ; where c = Q/mθ = specific heat capacity; m = mass; θ = temperature change.
FAQ
Common questions and clear answers for this topic.
Heat is a form of energy that transfers between objects or systems due to a temperature difference, moving from a hotter body to a cooler one until thermal equilibrium is reached.
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