Practice Questions

Q9. A source supplies heat to a system at the rate of 1000 W . If the system performs work at a rate of 200 W . The rate at which internal energy of the system increases is (1) 600 W (2) 800 W (3) 500 W (4) 1200 W

Q9. The variation of kinetic energy (KE) of a particle executing simple harmonic motion with the displacement (𝑥) starting from mean position to extreme position (𝐴) is given by (1) (2) (3) (4)

Q9. Every planet revolves around the sun in an elliptical orbit : A. The force acting on a planet is inversely proportional to square of distance from sun. B. Force acting on planet is inversely proportional to product of the masses of the planet and the sun. C. The centripetal force acting on the planet is directed away from the sun. D. The square of time period of revolution of planet around sun is directly proportional to cube of semi-major axis of elliptical orbit. Choose the correct answer from the options given below : (1) A and D only (2) C and D only (3) B and C only (4) A and C only

Q9. For a periodic motion represented by the equation 𝑦= sinω𝑡+ cosω𝑡 the amplitude of the motion is (1) 1 (2) 0 . 5 (3) 2 (4) √2

Q9. A hydraulic automobile lift is designed to lift vehicles of mass 5000 kg. The area of cross section of the cylinder carrying load is 250 cm2 . The maximum pressure the smaller piston would have to bear is [Assume g = 10 m s−2 ] (1) 20 × 106 Pa (2) 2 × 105 Pa (3) 200 × 106 Pa (4) 2 × 106 Pa

Q10.A steel wire with mass per unit length 7 . 0 × 10 – 3 kg m – 1 is under tension of 70 N. The speed of transverse waves in the wire will be: (1) 200π m s-1 (2) 100 m s-1 (3) 10 m s-1 (4) 50 m s-1

Q10.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion (A) : Steel is used in the construction of buildings and bridges. Reason (R) : Steel is more elastic and its elastic limit is high. In the light of above statements, choose the most appropriate answer from the options given below (1) Both A and R are correct and R is the correct (2) Both A and R are correct but R is NOT the explanation of A correct explanation of A (3) A is correct but R is not correct (4) A is not correct but R is correct

Q10.The number of air molecules per cm3 is increased from 3 × 1019 to 12 × 1019 . The ratio of collision frequency of air molecules before and after the increase in number respectively is : (1) 0 . 75 (2) 1 . 25 (3) 0 . 50 (4) 0 . 25

Q10.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A: When you squeeze one end of a tube to get toothpaste out from the other end, Pascal’s principle is observed. Reason R: A change in the pressure applied to an enclosed incompressible fluid is transmitted undiminished to every portion of the fluid and to the walls of its container. In the light of the above statements, choose the most appropriate answer from the options given below. (1) Both A and R are correct but R is NOT the (2) A is not correct but R is correct correct explanation of A (3) A is correct but R is not correct (4) Both A and R is correct and R is the correct explanation of A

Q10.If two charges 𝑞1and 𝑞2 are separated with distance 𝑑 and placed in a medium of dielectric constant 𝑘. What will be the equivalent distance between charges in air for the same electrostatic force? (1) 𝑑√𝑘 (2) 𝑘√𝑑 (3) 1 . 5𝑑√𝑘 (4) 2𝑑√𝑘

Q11.The electric field due to a short electric dipole at a large distance (r) from center of dipole on the equatorial plane varies with distance as : (1) r (2) 1 r2 (3) 1 (4) 1r r3

Q11.In a metallic conductor, under the effect of applied electric field, the free electrons of the conductor (1) Drift from higher potential to lower potential (2) Move with the uniform velocity throughout from lower potential to higher potential (3) Move in the straight line paths in the same (4) Move in the curved paths from lower potential to direction higher potential

Q11.The thermodynamic process, in which internal energy of the system remains constant is (1) Isochoric (2) Adiabatic (3) Isothermal (4) Isobaric

Q11.The equivalent capacitance of the combination shown is (1) 2 C (2) 5 C 3 C (3) (4) 4 C 2

Q11. Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : If dQ and dW represent the heat supplied to the system and the work done on the system respectively. Then according to the first law of thermodynamics dQ = dU −dW . Reason R : First law of thermodynamics is based on law of conservation of energy. In the light of the above statements, choose the correct answer from the option given below : (1) A is correct but R is not correct (2) A is not correct but R is correct (3) Both A and R are correct and R is the correct (4) Both A and R are correct but R is not the correct explanation of A explanation of A

Q11.For a uniformly charged thin spherical shell, the electric potential 𝑉 radially away from the centre 𝑂 of shell can be graphically represented as (1) (2) (3) (4) JEE Main 2023 (06 Apr Shift 1) JEE Main Previous Year Paper

Q12.A bicycle tyre is filled with air having pressure of 270 kPa at 27°C. The approximate pressure of the air in the tyre when the temperature increases to 36°C is (1) 270 kPa (2) 262 kPa (3) 278 kPa (4) 360 kPa

Q12.For three low density gases A, B, C pressure versus temperature graphs are plotted while keeping them at constant volume, as shown in the figure The temperature corresponding to the point ′K′ is: (1) −273°C (2) −100°C (3) –373°C (4) −40°C

Q12.The temperature of an ideal gas is increased from 200 K to 800 K . If r.m.s. speed of gas at 200 K is v0 . Then, r.m.s. speed of the gas at 800 K will be: (1) v0 (2) v0 4 (3) 4v0 (4) 2v0

Q12.The drift velocity of electrons for a conductor connected in an electrical circuit is 𝑉𝑑. The conductor is now replaced by another conductor with same material and same length but double the area of cross-section. The applied voltage remains same. The new drift velocity of electrons will be JEE Main 2023 (31 Jan Shift 1) JEE Main Previous Year Paper 𝑉𝑑 (1) 𝑉𝑑 (2) 2 (3) 𝑉𝑑 (4) 2𝑉𝑑 4

Q12.A flask contains hydrogen and oxygen in the ratio of 2 : 1 by mass at temperature 27 °C. The ratio of average kinetic energy per molecule of hydrogen and oxygen respectively is : (1) 2 : 1 (2) 1 : 1 (3) 1 : 4 (4) 4 : 1

Q12.The temperature at which the kinetic energy of oxygen molecules becomes double than its value at 27°C is (1) 927°C (2) 327°C (3) 1227°C (4) 627°C

Q13.For a solid rod, the Young's modulus of elasticity is 3. 2 × 1011 N m−2 and density is 8 × 103 kg m−3 . The velocity of longitudinal wave in the rod will be (1) 145. 75 × 103 m s−1 (2) 3. 65 × 103 m s−1 (3) 18. 96 × 103 m s−1 (4) 6. 32 × 103 m s−1

Q13.Match List I with List II : List I List II AIsothermal I Work done by the gas decreases internal energy Process B Adiabatic Process II No change in internal energy The heat absorbed goes partly to increase internal energy and partly to do C Isochoric Process III work DIsobaric Process IVNo work is done on or by the gas Choose the correct answer from the options given below : (1) A-II, B-I, C-III, D-IV (2) A-II, B-I, C-IV, D-III (3) A-I, B-II, C-IV, D-III (4) A-I, B-II, C-III, D-IV

Q13.The root mean square velocity of molecules of gas is (1) Proportional to square of temperature ( T 2 ). (2) Inversely proportional to square root of temperature ( ). √1T (3) Proportional to square root of temperature √T . (4) Proportional to temperature (T).