Physics
Heat
Easy
Question
A fixed mass of a gas is adiabatically made to expand to double its volume and then isochorically heated to bring the gas to the original pressure . The ratio of final to initial temperature will be
- 1 : 1
- 2 : 1
- 1 : 2
- Depends on the atomicity of the gas.
The correct answer is: 2 : 1
Such problems can be tackled easily, by considering only the final and initial states and applying the equation of state n=constant, i.e., PV/T= constant. Evidently, the pressure is the same but volume gets doubled and so, T also gets doubled.
Related Questions to study
Physics
Find the amount of work done to increase the temperature of one mole of an ideal gas by 30°C , if it is expanding under condition 
. R is gas constant
Find the amount of work done to increase the temperature of one mole of an ideal gas by 30°C , if it is expanding under condition . R is gas constant
PhysicsHeat
Physics
During an experiment an ideal gas is found to obey an additional law VP2 = constant. The gas is initially at temperature T and volume V. What wiII be the temperature of the gas when it expands to a volume 2V?
During an experiment an ideal gas is found to obey an additional law VP2 = constant. The gas is initially at temperature T and volume V. What wiII be the temperature of the gas when it expands to a volume 2V?
PhysicsHeat
Physics
A polytropic process for an ideal gas is represented by equation PVn = constant. If g is ratio of specific heats 
, then value of n for which molar heat capacity of the process is negative, is given as :
A polytropic process for an ideal gas is represented by equation PVn = constant. If g is ratio of specific heats , then value of n for which molar heat capacity of the process is negative, is given as :
PhysicsHeat
Physics
If the ratio of specific heat of a gas at constant pressure to that at constant volume is 
, the change i n internal energy of the mass of gas , when the volume changes from V to 2V at constant pressure p , is
If the ratio of specific heat of a gas at constant pressure to that at constant volume is , the change i n internal energy of the mass of gas , when the volume changes from V to 2V at constant pressure p , is
PhysicsHeat
Physics
One mole of an idea l gas at a temperature T1K expands slowly according to the law 
Its final temperature is T2K . The work done by the gas is
One mole of an idea l gas at a temperature T1K expands slowly according to the law Its final temperature is T2K . The work done by the gas is
PhysicsHeat
Physics
Initial volume of three samples of same gas A,B and C are same. The process A is adiabatic, B is isobaric and C is isothermal. Each of the sample has same final pressure and volume. The initial pressure of which sample was maximum.
Initial volume of three samples of same gas A,B and C are same. The process A is adiabatic, B is isobaric and C is isothermal. Each of the sample has same final pressure and volume. The initial pressure of which sample was maximum.
PhysicsHeat
Physics
In an adiabatic process 
. The pressure of the gas Will be proportional to :
In an adiabatic process . The pressure of the gas Will be proportional to :
PhysicsHeat
Physics
p- V diagram of a diatomic gas is a straight line passing through origin . The molar heat capacity of the gas in the process wilI be :
p- V diagram of a diatomic gas is a straight line passing through origin . The molar heat capacity of the gas in the process wilI be :
PhysicsHeat
Physics
During adiabatic process pressure P versus density 
equation is:
During adiabatic process pressure P versus density equation is:
PhysicsHeat
Physics
An ideal gas A and b have their volumes, increased from V to 2V isothermal conditions. The increase in internal energy
An ideal gas A and b have their volumes, increased from V to 2V isothermal conditions. The increase in internal energy
PhysicsHeat
Physics
A monoatomic gas is supplied heat Q very slowly keeping the pressure constant. The work done by the gas is
A monoatomic gas is supplied heat Q very slowly keeping the pressure constant. The work done by the gas is
PhysicsHeat
Physics
1g mole of an ideal gas at STP is subjected to a reversible adiabatic expansion to double its volume. Find the change in internal energy 
1g mole of an ideal gas at STP is subjected to a reversible adiabatic expansion to double its volume. Find the change in internal energy
PhysicsHeat
Physics
A gas mixture of 2 moles of oxygen and a 4 mole of Ar at temperature T. Neglecting all vibrations modes, the total internal energy of the system is
A gas mixture of 2 moles of oxygen and a 4 mole of Ar at temperature T. Neglecting all vibrations modes, the total internal energy of the system is
PhysicsHeat
Physics
A gas undergoes a cyclic process ABCDA as shown in the figure. The part ABC of process is semi-circular. The work done by the gas is:
A gas undergoes a cyclic process ABCDA as shown in the figure. The part ABC of process is semi-circular. The work done by the gas is:
PhysicsHeat
Physics
Q cal of heat is required to raise the temperature of 1mole of a monatomic gas from 20°C to 30°C at constant pressure. The amount of heat required to raise the temperature of 1 mole of diatomic gas from 20°C to 25°C at constant pressure is:
Q cal of heat is required to raise the temperature of 1mole of a monatomic gas from 20°C to 30°C at constant pressure. The amount of heat required to raise the temperature of 1 mole of diatomic gas from 20°C to 25°C at constant pressure is:
PhysicsHeat
