PHYSICS
BANSAL CLASSES Target IIT JEE 2007 CLASS: XI (PQRS) DATE: 25-26/11/2005
Daily Practice Problems MAX. TIME: 60 Min. DPP. NO.-"76
Q.l
An ideal gas of Molar mass M is contained in a vertical tube of height H, closed at both ends. The tube is accelerating vertically upwards with acceleration g. Then, the ratio of pressure at the bottom and the mid point ofthe tube will be (A) exp[2MgHXRT] (B) exp[-2MgH/RT] (C) exp[MgH/RT] (D) MgH/RT
Q.2
Considere the thermodynamics cycle shown on PV diagram. The process A -» B is isobaric, B -* C is isochoric and C -» A is a straight line process. The following internal energy and heat are given: AUa B = + 400 kJ and QB ^ c = - 500 kJ The heat flow in the process Q c __>Ais: (A) - 20 kJ (B) + 25 kJ (C)-25kJ (D) Data are insufficient
Q.3
1 kg ofa gas does 20 kJofwork and receives 16 kJofheat when it is expanded between two states. A second kind of expansion can be found between the initial and final state which requires a heat input of 9 kJ. The work done by the gas in the second expansion is: (A) 32 kJ (B) 5 kJ (C)-4kJ (D)13kJ
Q. 4
A vessel contains an ideal monoatomic gas which expands at constant pressure, when heat Q is given to it. Then the work done in expansion is: (A)Q
Q.5
(B)|Q
(C)|Q
(D)|Q
One mole of an ideal monoatomic gas at temperature T0 expands slowly according to the law P/V = constant. If the final temperature is 2 T0, heat supplied to the gas is: (A)2RT 0
(B)|RT0
(C)RT q
(D) | RT 0
Q. 6
One mole of a gas expands with temperature according to the relation V = kT2/3. What is the workdone when the temperature changes by 30°C? (A)10R (B) 20R (C) 3 OR (D) 40R
Q.7
One mole ofa gas (y = 1.5) is taken through a cycle AB CD where, AB —> adiabatic process BC -»isothermal process CD -> isobaric process AB -» adiabatic process Find the work done by the gas and also change in its internal energy in each process. Also find heat exchanged in each process.
Q.8
Determine the work W done by an ideal gas during a closed cycle 1 -»4->3-»2-» 1 shown in the Figure if pj = 105Pa, p0 = 3 x 105Pa, p2 = 4 x 105Pa, V 2 -Vj = 10/, and segments 4-3 and 2-1 ofthe cycle are parallel to the Y-axis.