Practice Questions

Q8. Correct Bernoulli's equation is (symbols have their usual meaning) : (1) P + mgh + 12 mv2 = constant (2) P + ρgh + 21 ρv2 = constant (3) P + ρgh + ρv2 = constant (4) P + 12 ρgh + 21 ρv2 = constant JEE Main 2024 (08 Apr Shift 1) JEE Main Previous Year Paper

Q8. Given below are two statements: Statement I : When speed of liquid is zero everywhere, pressure difference at any two points depends on equation P1 −P2 = ρg (h2 −h1). Statement II : In ventury tube shown 2gh = v21 −v22 In the light of the above statements, choose the most appropriate answer from the options given below. (1) Both Statement I and Statement II are correct. (2) Statement I is correct but Statement II is incorrect. (3) Statement I is incorrect but Statement II is (4) Both Statement I and Statement II are incorrect. correct.

Q8. With rise in temperature, the Young's modulus of elasticity (1) changes erratically (2) decreases (3) increases (4) remains unchanged

Q8. Four identical particles of mass 𝑚 are kept at the four corners of a square. If the gravitational force exerted on 2√2 + 1 𝐺𝑚2 one of the masses by the other masses is , the length of the sides of the square is 32 𝐿2 𝐿 (1) (2) 4𝐿 2 (3) 3𝐿 (4) 2𝐿

Q8. A gas mixture consists of 8 moles of argon and 6 moles of oxygen at temperature 𝑇. Neglecting all vibrational modes, the total internal energy of the system is (1) 29 𝑅𝑇 (2) 20 𝑅𝑇 (3) 27 𝑅𝑇 (4) 21 𝑅𝑇

Q8. During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute 𝐶𝑝 temperature. The ratio of for the gas is : 𝐶𝑣 (1) 5 (2) 3 3 2 7 9 (3) (4) 5 7

Q8. The temperature of a gas is −78∘C and the average translational kinetic energy of its molecules is K. The temperature at which the average translational kinetic energy of the molecules of the same gas becomes 2 K is : (1) 127∘C (2) 117∘C (3) −39∘C (4) −78∘C

Q8. A small ball of mass m and density ρ is dropped in a viscous liquid of density ρ0 . After sometime, the ball falls with constant velocity. The viscous force on the ball is : JEE Main 2024 (06 Apr Shift 1) JEE Main Previous Year Paper (1) mg (1 −ρρ0) (2) mg (1 + ρ0ρ ) (3) mg ( ρ0ρ −1) (4) mg(1 −ρ0ρ ) ∇

Q8. In hydrogen like system the ratio of coul0mbian force and gravitational force between an electron and a proton is in the order of : (1) 1039 (2) 1029 (3) 1019 (4) 1036

Q8. A diatomic gas ( 𝛾= 1 . 4 ) does 200 J of work when it is expanded isobarically. The heat given to the gas in the process is : (1) 850 J (2) 800 J (3) 600 J (4) 700 J

Q8. Choose the correct statement for processes 𝐴 & 𝐵 shown in figure. (1) 𝑃𝑉𝛾= 𝑘 for process 𝐵 and 𝑃𝑉= 𝑘 for process 𝐴. (2) 𝑃𝑉= 𝑘 for process 𝐵 and 𝐴. 𝑃𝛾- 1 𝑇𝛾 (3) (4) 𝑘 for process 𝐵 and 𝑇= 𝑘 for process 𝐴. 𝑇𝛾= 𝑃𝛾- 1 = 𝑘 for process 𝐴 and 𝑃𝑉= 𝑘 for process 𝐵.

Q8. A diatomic gas (γ = 1.4) does 100 J of work in an isobaric expansion. The heat given to the gas is : (1) 250 J (2) 150 J (3) 350 J (4) 490 J

Q8. During an adiabatic process, if the pressure of a gas is found to be proportional to the cube of its absolute temperature, then the ratio of CP for the gas is : CV JEE Main 2024 (05 Apr Shift 2) JEE Main Previous Year Paper (1) 5 (2) 9 3 7 (3) 3 (4) 7 2 5

Q8. A sample of gas at temperature T is adiabatically expanded to double its volume. Adiabatic constant for the gas is γ = 3/2. The work done by the gas in the process is: (μ = 1 mole) (1) RT[1 −2√2] (2) RT[√2 −2] (3) RT[2 −√2] (4) RT[2√2 −1]

Q8. A small liquid drop of radius R is divided into 27 identical liquid drops. If the surface tension is T , then the work done in the process will be : (1) 8πR2T (2) 3πR2T (3) 1 πR2T (4) 4πR2T 8

Q8. At which temperature the r.m.s. velocity of a hydrogen molecule equal to that of an oxygen molecule at 47°C ? (1) 80 K (2) −73 K (3) 4 K (4) 20 K

Q8. A total of 48 J heat is given to one mole of helium kept in a cylinder. The temperature of helium increases by 2∘C. The work done by the gas is: Given, R = 8.3 J K−1 mol−1 . JEE Main 2024 (06 Apr Shift 2) JEE Main Previous Year Paper (1) 24.9 J (2) 72.9 J (3) 48 J (4) 23.1 J

Q9. If three moles of monoatomic gas 𝛾= 5 is mixed with two moles of a diatomic gas 𝛾= 7 the value of adiabatic 3 5, exponent 𝛾 for the mixture is: (1) 1 . 75 (2) 1 . 40 (3) 1 . 52 (4) 1 . 35

Q9. The speed of sound in oxygen at S.T.P. will be approximately: (Given, 𝑅= 8 . 3 J K-1, 𝛾= 1 . 4) (1) 310 m s-1 (2) 333 m s-1 (3) 341 m s-1 (4) 325 m s-1

Q9. The volume of an ideal gas (γ = 1.5) is changed adiabatically from 5 litres to 4 litres. The ratio of initial pressure to final pressure is: JEE Main 2024 (09 Apr Shift 1) JEE Main Previous Year Paper (1) 16 (2) 4 25 5 (3) 8 (4) 2 5√5 √5

Q9. Two vessels A and B are of the same size and are at same temperature. A contains 1 g of hydrogen and B contains 1 g of oxygen. PA and PB are the pressures of the gases in A and B respectively, then PA is : PB (1) 16 (2) 8 (3) 4 (4) 32

Q9. Five charges +q, +5q, −2q, +3q and −4q are situated as shown in the figure. The electric flux due to this configuration through the surface S is : (1) 4q (2) 5q ϵ0 ϵ0 (3) q (4) 3q ϵ0 ϵ0

Q9. Two different adiabatic paths for the same gas intersect two isothermal curves as shown in P-V diagram. The relation between the ratio Va and the ratio Vb is: Vd Vc (1) Va ≠Vb (2) Va = Vb Vd Vc Vd Vc (3) Va Vb −1 (4) Va Vb 2 = = Vd ( Vc ) Vd ( Vc )

Q9. Given below are two statements : Statement (I) : The mean free path of gas molecules is inversely proportional to square of molecular diameter. Statement (II) : Average kinetic energy of gas molecules is directly proportional to absolute temperature of gas. In the light of the above statements, choose the correct answer from the options given below : (1) Statement I is true but Statement II is false (2) Both Statement I and Statement II are false (3) Both Statement I and Statement II are true (4) Statement I is false but Statement II is true

Q9. The pressure and volume of an ideal gas are related as 𝑃𝑉 32 = 𝐾 (Constant). The work done when the gas is taken from state 𝐴𝑃1, 𝑉1, 𝑇1 to state 𝐵𝑃2, 𝑉2, 𝑇2 is : (1) 2 ( 𝑃1𝑉1 - 𝑃2𝑉2 ) (2) 2 ( 𝑃2𝑉2 - 𝑃1𝑉1 ) (3) 2√𝑃1𝑉1 −√𝑃2𝑉2 (4) 2𝑃2√𝑉2 −𝑃1√𝑉1