Advertisements
Advertisements
प्रश्न
The first law of thermodynamics is a statement of ____________ .
पर्याय
conservation of heat
conservation of work
conservation of momentum
conservation of energy
उत्तर
conservation of energy
Heat is a form of energy. Since the first law of thermodynamics deals with the conservation of heat, it actually refers to the conservation of energy in the broader sense.
The first law of thermodynamics is just the restatement of the law of conservation of energy. We observe that the energy supplied to a system will contribute to change in its internal energy and the amount of work done by the system on its surroundings.
APPEARS IN
संबंधित प्रश्न
Figure shows the variation in the internal energy U with the volume V of 2.0 mol of an ideal gas in a cyclic process abcda. The temperatures of the gas at b and c are 500 K and 300 K respectively. Calculate the heat absorbed by the gas during the process.
Find the change in the internal energy of 2 kg of water as it is heated from 0°C to 4°C. The specific heat capacity of water is 4200 J kg−1 K−1 and its densities at 0°C and 4°C are 999.9 kg m−3 and 1000 kg m−3 respectively. Atmospheric pressure = 105 Pa.
For an Isothermal process
For an Isochoric process
Consider two containers A and B containing identical gases at the same pressure, volume and temperature. The gas in container A is compressed to half of its original volume isothermally while the gas in container B is compressed to half of its original value adiabatically. The ratio of final pressure of gas in B to that of gas in A is ______.
Three copper blocks of masses M1, M2 and M3 kg respectively are brought into thermal contact till they reach equilibrium. Before contact, they were at T1, T2, T3 (T1 > T2 > T3). Assuming there is no heat loss to the surroundings, the equilibrium temprature T is (s is specific heat of copper)
The first law of thermodynamics is concerned with the conservation of ______.
One mole of an ideal gas is allowed to expand reversibly and adiabatically from a temperature of 27°C. If the work done during the process is 3 kJ, the final temperature will be equal to ______.
(Cv = 20 JK−1)
Which among the following equations represents the first law of thermodynamics under isobaric conditions?
The amount of work done in increasing the voltage across the plates of capacitor from 5 V to 10 V is W. The work done in increasing it from 10 V to 15 V will be ______.
An ideal gas (γ = 1.5) is expanded adiabatically. How many times has the gas had to be expanded to reduce the root mean square velocity of molecules two times?
In an adiabatic process, ______.
For an isothermal and reversible expansion of 0.5 mol of an ideal gas Wmax is - 3.918 kJ. The value of ΔU is ______.
Explain the formulation of first law of thrmodynamics.
Consider the cyclic process ABCA on a sample of 2.0 mol of an ideal gas as shown in following figure. The temperature of the gas at A and B are 300 K and 500 K respectively. A total of 1200 J heat is withdrawn from the sample in this process. Find the work done by the gas in part BC. (R = 8.3 J/mol K)
Calculate work done when 2 moles of ideal gas expands by 5 dm3 isothermally at pressure 1.2 bar.
Write a short note on isobar.