Advertisements
Advertisements
Question
A substance is taken through the process abc as shown in figure. If the internal energy of the substance increases by 5000 J and a heat of 2625 cal is given to the system, calculate the value of J.

Advertisements
Solution
Given:-
Heat given to the system, ∆Q = 2625 cal
Increase in the internal energy of the system, ∆U = 5000 J

From the graph, we get
W = Area of the rectangle formed under line ab + Area under line bc
For line BC:-
Change in volume = 0
WBC = P Δ V = 0
∆W = Area of the rectangle
∆W = 200 × 103 × 0.03
= 6000 J
We know,
∆Q = ∆W + ∆U
⇒ 2625 cal = 6000 J + 5000 J
\[\Rightarrow J = \frac{11000}{2625} = 4 . 19 \text{ J/cal}\]
APPEARS IN
RELATED QUESTIONS
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:
Do the intermediate states of the system (before settling to the final equilibrium state) lie on its P-V-T surface?
Should the internal energy of a system necessarily increase if its temperature is increased?
Refer to figure. Let ∆U1 and ∆U2 be the changes in internal energy of the system in the process A and B. Then _____________ .

An ideal gas goes from the state i to the state f as shown in figure. The work done by the gas during the process ______________ .

What is the energy associated with the random, disordered motion of the molecules of a system called as?
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?
When does a system lose energy to its surroundings and its internal energy decreases?
Explain the different ways through which the internal energy of the system can be changed.
One gram of water (1 cm3) becomes 1671 cm3 of steam at a pressure of 1 atm. The latent heat of vaporization at this pressure is 2256 J/g. Calculate the external work and the increase in internal energy.
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 ____________.
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 the temperature of the gas?
n mole of a perfect gas undergoes a cyclic process ABCA (see figure) consisting of the following processes:
A `→` B: Isothermal expansion at temperature T so that the volume is doubled from V1 to V2 = 2V1 and pressure changes from P1 to P2.
B `→` C: Isobaric compression at pressure P2 to initial volume V1.
C `→` A: Isochoric change leading to change of pressure from P2 to P1.
Total workdone in the complete cycle ABCA is ______.

In thermodynamics, heat and work are ______.
A steam engine delivers 4.8 x 108 Jof work per minute and services 1.2 x 109 J of heat per minute from its boiler. What is the percentage efficiency of the engine?
A system releases 125 kJ of heat while 104 kJ work is done on the system. Calculate the change in internal energy.
