Practice Questions

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 temperature of a gas having 2. 0 × 1025 molecules per cubic meter at 1. 38 atm (Given, k = 1. 38 × 10−23J K−1) is : (1) 500 K (2) 200 K (3) 100 K (4) 300 K

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. The resistances of the platinum wire of a platinum resistance thermometer at the ice point and steam point are 8Ω and 10Ω respectively. After inserting in a hot bath of temperature 400∘C , the resistance of platinum wire is : (1) 10Ω (2) 8Ω (3) 16Ω (4) 2Ω

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. 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

Q9. A sample contains mixture of helium and oxygen gas. The ratio of root mean square speed of helium and oxygen in the sample, is: (1) 1 (2) 2√2 32 1 (3) 1 (4) 1 2√2 4

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. If n is the number density and d is the diameter of the molecule, then the average distance covered by a molecule between two successive collisions (i.e. mean free path) is represented by : (1) √2nπd2 (2) 1 √2nπd2 (3) 1 (4) 1 √2nπd2 √2n2π2d2

Q9.Match List I with List II : (1) (A)-(III), (B)-(IV), (C)-(I), (D)-(II) (2) (A)-(II), (B)-(I), (C)-(IV), (D)-(III) (3) (A)-(I), (B)-(II), (C)-(III), (D)-(IV) (4) (A)-(I), (B)-(IV), (C)-(II), (D)-(III)

Q9. Two thermodynamical process are shown in the figure. The molar heat capacity for process A and B are CA and CB . The molar heat capacity at constant pressure and constant volume are represented by CP and CV , respectively. Choose the correct statement. (1) CP > CB > CV (2) CA = 0 and CB = ∞ (3) CP > CV > CA = CB (4) CA > CP > CV

Q9. The translational degrees of freedom (ft) and rotational degrees of freedom (fr) of CH4 molecule are: (1) ft = 2 and fr = 2 (2) ft = 3 and fr = 3 (3) ft = 3 and fr = 2 (4) ft = 2 and fr = 3

Q10.Two charges of 5Q and −2Q are situated at the points (3a, 0) and (−5a, 0) respectively. The electric flux through a sphere of radius 4a having centre at origin is: (1) 2Q (2) 5Q ε0 ε0 (3) 7Q (4) 3Q ε0 ε0

Q10.The effective resistance between A and B, if resistance of each resistor is R, will be (1) 8R (2) 5R 3 3 (3) 4R (4) 2 R 3 3

Q10.A bulb and a capacitor are connected in series across an ac supply. A dielectric is then placed between the plates of the capacitor. The glow of the bulb: (1) increases (2) decreases (3) remains same (4) becomes zero

Q10.In simple harmonic motion, the total mechanical energy of given system is E . If mass of oscillating particle P is doubled then the new energy of the system for same amplitude is: (1) E (2) E/√2 (3) 2E (4) E√2

Q10.The given figure represents two isobaric processes for the same mass of an ideal gas, then (1) 𝑃2 ≥𝑃1 (2) 𝑃2 > 𝑃1 (3) 𝑃1 = 𝑃2 (4) 𝑃1 > 𝑃2

Q10.The specific heat at constant pressure of a real gas obeying PV 2 = RT equation is: (1) R 3 + CV (2) CV + R (3) CV + 2VR (4) R

Q10. N moles of a polyatomic gas (f = 6) must be mixed with two moles of a monoatomic gas so that the mixture behaves as a diatomic gas. The value of N is: (1) 6 (2) 3 (3) 4 (4) 2 N C−1 . The electric flux through a surface area 30ˆi m2 lying in

Q10.Force between two point charges 𝑞1 and 𝑞2 placed in vacuum at 𝑟 cm apart is 𝐹. Force between them when placed in a medium having dielectric 𝐾= 5 at 𝑟 cm apart will be: 5 𝐹 (1) (2) 5𝐹 25 (3) 𝐹 (4) 25𝐹 5

Q10.A plane progressive wave is given by y = 2 cos 2π(330t −x)m . The frequency of the wave is : (1) 330 Hz (2) 660 Hz (3) 340 Hz (4) 165 Hz

Q10.Given below are two statements : Statement I : When a capillary tube is dipped into a liquid, the liquid neither rises nor falls in the capillary. The contact angle may be 0∘ . Statement II : The contact angle between a solid and a liquid is a property of the material of the solid and liquid as well. In the light of the above statement, choose the correct answer from the options given below. (1) Both Statement I and Statement II are false (2) Both Statement I and Statement II are true (3) Statement I is false but Statement II is true (4) Statement I is true and Statement II is false

Q10.An electric charge 10−6 μC is placed at origin (0, 0) m of X −Y co-ordinate system. Two points P and Q are situated at m and m respectively. The potential difference between the points P and Q (√3, √3) (√6, 0) will be : (1) √3 V (2) √6 V (3) 0 V (4) 3 V

Q10.The vehicles carrying inflammable fluids usually have metallic chains touching the ground : (1) To protect tyres from catching dirt from ground (2) To alert other vehicles (3) It is a custom (4) To conduct excess charge due to air friction to ground and prevent sparking

Q10.A mixture of one mole of monoatomic gas and one mole of a diatomic gas (rigid) are kept at room temperature (27∘C). The ratio of specific heat of gases at constant volume respectively is: (1) 7 (2) 3 5 5 (3) 5 (4) 3 3 2