Which of the following cases (if any) requires the greatest amount of heat? (In each case, the material is the same).
Correct answer: D. The amount of heat required is the same in each of the three previous cases
- A. 1.5 kg of the material is to be heated by 7.0 C°
- B. 3.0 kg of the material is to be heated by 3.5 C°
- C. 0.50 kg of the material is to be heated by 21 C°
- D. The amount of heat required is the same in each of the three previous cases
Explanation
When an object is heated, it's temperature changes over a period of time. The heat required is given by;q = mc∆TWhere q is given heat, m is mass in kg and t is the temperature change of the material and c is the specific heat of the material.Since material is the same for all three cases, c is the same for all of them. Therefore, heat given is directly proportional to mass and temperate change.In the first case; q = 1.5×c×7 = 10.5cIn the second case; q = 3×c×3.5 = 10.5cIn the third case; q = 0.5×c×21 = 10.5cAs observed the heat required is the same for all so option D is correct.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Thermal Equilibrium and Heat
Thermal equilibrium means that bodies in contact have the same temperature and no net heat flows between them. The topic distinguishes heat from temperature, uses the zeroth law of thermodynamics, and covers heat transfer, specific heat capacity, thermal expansion and the conditions for reaching equilibrium.
Practise Thermodynamics
714 free Thermodynamics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Thermal Equilibrium and Heat questions
The value of the triple point of water is:
Two objects, with different sizes, masses, and temperatures, are placed in thermal contact. In which direction does the energy travel?
The specific latent heat of the fusion of ice is 334 J/g. How much energy is needed to melt 2 kg of ice at 0˚C?
A 300 W heater is used to boil 500g of water at 100˚C. How long should the heater be switched on? (The specific latent heat of vaporization of water is 2230 J/g)
Which one of the following is not a state function?
When a gas is compressed isothermally, the product of its pressure and volume during the process is: