Advertisements
Advertisements
प्रश्न
A system releases 100 kJ of heat while 80 kJ of work is done on the system. Calculate the change in internal energy.
Advertisements
उत्तर
Q = -100 kJ
W = -80 kJ
Q = ΔU + W
-100 = ΔU - 80
-100 + 80 = ΔU
ΔU = -20 kJ
APPEARS IN
संबंधित प्रश्न
Explain why Air pressure in a car tyre increases during driving.
Should the internal energy of a system necessarily increase if its temperature is increased?
The outer surface of a cylinder containing a gas is rubbed vigorously by a polishing machine. The cylinder and its gas become warm. Is the energy transferred to the gas heat or work?
The final volume of a system is equal to the initial volume in a certain process. Is the work done by the system necessarily zero? Is it necessarily nonzero?
When a tyre bursts, the air coming out is cooler than the surrounding air. Explain.
Figure shows two processes A and B on a system. Let ∆Q1 and ∆Q2 be the heat given to the system in processes A and B respectively. Then ____________ .
Consider two processes on a system as shown in figure.
The volumes in the initial states are the same in the two processes and the volumes in the final states are also the same. Let ∆W1 and ∆W2 be the work done by the system in the processes A and B respectively.
A gas is contained in a metallic cylinder fitted with a piston. The piston is suddenly moved in to compress the gas and is maintained at this position. As time passes the pressure of the gas in the cylinder ______________ .
The pressure p and volume V of an ideal gas both increase in a process.
(a) Such a process is not possible.
(b) The work done by the system is positive.
(c) The temperature of the system must increase.
(d) Heat supplied to the gas is equal to the change in internal energy.
In a process on a system, the initial pressure and volume are equal to the final pressure and volume.
(a) The initial temperature must be equal to the final temperature.
(b) The initial internal energy must be equal to the final internal energy.
(c) The net heat given to the system in the process must be zero.
(d) The net work done by the system in the process must be zero.
A gas is taken along the path AB as shown in figure. If 70 cal of heat is extracted from the gas in the process, calculate the change in the internal energy of the system.
Which of the following is correct, when the energy is transferred to a system from its environment?
Which of the following system freely allows the exchange of energy and matter with its environment?
Define heat.
What is the internal energy of the system, when the amount of heat Q is added to the system and the system does not do any work during the process?
derive the relation between the change in internal energy (∆U), work is done (W), and heat (Q).
A thermodynamic system goes from states (i) P, V to 2P, V (ii) P, V to P, 2V. The work done in the two cases is ______.
An ideal gas is compressed at a constant temperature. Its internal energy will ____________.
In a thermodynamic system, working substance is ideal gas. Its internal energy is in the form of ______.
8 m3 of a gas is heated at the pressure 105 N/m2 until its volume increases by 10%. Then, the external work done by the gas is ____________.
Which of the following represents isothermal process?
Two cylinders A and B of equal capacity are connected to each other via a stopcock. A contains a gas at standard temperature and pressure. B is completely evacuated. The entire system is thermally insulated. The stopcock is suddenly opened. Answer the following:
What is the change in internal energy of the gas?
In insulated systems, the amount of external work done by the gas is proportional to:
A person of mass 60 kg wants to lose 5kg by going up and down a 10 m high stairs. Assume he burns twice as much fat while going up than coming down. If 1 kg of fat is burnt on expending 7000 kilo calories, how many times must he go up and down to reduce his weight by 5 kg?
The internal energy of one mole of argon is ______.
The internal energy of one mole of argon at 300 K is ______. (R = 8.314 J/mol.K)
