Advertisements
Advertisements
प्रश्न
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
उत्तर
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
संबंधित प्रश्न
Explain why Air pressure in a car tyre increases during driving.
A steam engine delivers 5.4×108 J of work per minute and services 3.6 × 109 J of heat per minute from its boiler. What is the efficiency of the engine? How much heat is wasted per minute?
Should the internal energy of a system necessarily increase if heat is added to it?
A force F is applied on a block of mass M. The block is displaced through a distance d in the direction of the force. What is the work done by the force on the block? Does the internal energy change because of this work?
When a tyre bursts, the air coming out is cooler than the surrounding air. Explain.
Consider the following two statements.
(A) If heat is added to a system, its temperature must increase.
(B) If positive work is done by a system in a thermodynamic process, its volume must increase.
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 system releases 130 kJ of heat while 109 kJ of work is done on the system. Calculate the change in internal energy.
What is the energy associated with the random, disordered motion of the molecules of a system called as?
When does a system lose energy to its surroundings and its internal energy decreases?
A system releases 100 kJ of heat while 80 kJ of work is done on the system. Calculate the change in internal energy.
derive the relation between the change in internal energy (∆U), work is done (W), and heat (Q).
The internal energy of a system is ______
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 ______.
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 final pressure of the gas in A and B?
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?
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.
