Practice Questions

Q10.The Young's modulus of a steel wire of length 6 m and cross-sectional area 3 mm2 , is 2 × 1111 N/m2 . The wire is suspended from its support on a given planet. A block of mass 4 kg is attached to the free end of the JEE Main 2023 (01 Feb Shift 2) JEE Main Previous Year Paper wire. The acceleration due to gravity on the planet is 1 of its value on the earth. The elongation of wire is 4 (Take g on the earth = 10 m/s2 ): (1) 1 cm (2) 1 mm (3) 0. 1 mm (4) 0. 1 cm

Q10.The pressure ( 𝑃) and temperature ( 𝑇) relationship of an ideal gas obeys the equation 𝑃𝑇2 = constant. The volume expansion coefficient of the gas will be : 3 (1) 3𝑇2 (2) 𝑇2 3 3 (3) (4) 𝑇3 𝑇

Q10.A particle executes SHM of amplitude 𝐴. The distance from the mean position when its kinetic energy becomes equal to its potential energy is: (1) 1 (2) 2𝐴 √2𝐴 (3) √2𝐴 (4) 12𝐴

Q10.A particle executes S.H.M. of amplitude 𝐴 along 𝑥-axis. At 𝑡= 0, the position of the particle is 𝑥= and it 2 moves along positive 𝑥-axis. The displacement of particle in time 𝑡 is 𝑥= 𝐴 sin𝜔𝑡 + 𝛿, then the value 𝛿 will be (1) 𝜋 (2) 𝜋 2 6 𝜋 𝜋 (3) (4) 3 4

Q11.Which of the following correctly represents the variation of electric potential ( 𝑉) of a charged spherical conductor of radius ( 𝑅) with radial distance ( 𝑟) from the centre? (1) (2) (3) (4)

Q11.A body cools in 7 minutes from 60oC to 40oC. The temperature of the surrounding is 10oC. The temperature of the body after the next 7 minutes will be (1) 30oC (2) 32oC (3) 34oC (4) 28oC

Q11. The figure shows a liquid of given density flowing steadily in horizontal tube of varying cross-section. Cross- sectional areas at A is 1. 5 cm2, and B is 25 mm2, if the speed of liquid at B is 60 cm s−1 then (PA–PB) is (Given PA and PB are liquid pressures at A and B points. Density ρ = 1000 kg m−3 A and B are on the axis of tube) (1) 135 Pa (2) 27 Pa (3) 175 Pa (4) 36 Pa 5 ) 2 v, when v is the average

Q11.According to law of equipartition of energy the molar specific heat of a diatomic gas at constant volume where the molecule has one additional vibrational mode is :- (1) 9 R (2) 5 R 2 2 (3) 3 R (4) 7 R 2 2

Q11. A 10 𝜇C charge is divided into two parts and placed at 1 cm distance so that the repulsive force between them is maximum. The charges of the two parts are: (1) 7𝜇C, 3𝜇C (2) 8𝜇C, 2𝜇C (3) 5𝜇C, 5𝜇C (4) 9𝜇C, 1𝜇C

Q11.Two isolated metallic solid spheres of radii 𝑅 and 2𝑅 are charged such that both have same charge density 𝜎 . The spheres are then connected by a thin conducting wire. If the new charge density of the bigger sphere is 𝜎'. 𝜎' The ratio is : 𝜎 9 4 (1) (2) 4 3 5 5 (3) (4) 3 6

Q11.Heat energy of 735 J is given to a diatomic gas allowing the gas to expand at constant pressure. Each gas molecule rotates around an internal axis but do not oscillate. The increase in the internal energy of the gas will be: (1) 525 J (2) 441 J (3) 572 J (4) 735 J

Q11.An air bubble of volume 1 cm3 rises from the bottom of a lake 40 m deep to the surface at a temperature of 12°C. The atmospheric pressure is 1 × 105 Pa, the density of water is 1000 kg m−3 and g = 10 m s−2. There is no difference of the temperature of water at the depth of 40 m and on the surface. The volume of air bubble when it reaches the surface will be (1) 2 cm3 (2) 3 cm3 (3) 4 cm3 (4) 5 cm3

Q11.Let 𝜎 be the uniform surface charge density of two infinite thin plane sheets shown in figure. Then the electric fields in three different region 𝐸𝐼 , 𝐸𝐼𝐼 and 𝐸𝐼𝐼𝐼 (1) → 𝐸𝐼= 2𝜎 ^𝑛, →𝐸𝐼𝐼= 0, →𝐸𝐼𝐼𝐼= 2𝜎 ^𝑛 (2) →𝐸𝐼= 0, →𝐸𝐼𝐼= 𝜎 ^𝑛, →𝐸𝐼𝐼𝐼= 0 ∈0 ∈0 ∈0 → 𝜎 → → 𝜎 → -𝜎 → → 𝜎 (3) ^𝑛 𝐸𝐼= ^𝑛, 𝐸𝐼𝐼= 0, 𝐸𝐼𝐼𝐼= 𝐸𝐼= 2 ∈0 ^𝑛, 𝐸𝐼𝐼= 0, 𝐸𝐼𝐼𝐼= 2 ∈0 ^𝑛 (4) ∈0 ∈0

Q11.Work done by a Carnot engine operating between temperatures 127°C and 27°C is 2 kJ . The amount of heat transferred to the engine by the reservoir is: (1) 8 kJ (2) 2. 67 kJ (3) 2 kJ (4) 4 kJ

Q11. A bowl filled with very hot soup cools from 98°C to 86∘C in 2 minutes when the room temperature is 22∘C . How long it will take to cool from 75∘C to 69∘C ? (1) 2 minute (2) 1. 4 minute (3) 0. 5 minute (4) 1 minute

Q12.Two identical heater filaments are connected first in parallel and then in series. At the same applied voltage, the ratio of heat produced in same time for parallel to series will be: (1) 1: 4 (2) 4: 1 (3) 2: 1 (4) 1: 2 JEE Main 2023 (11 Apr Shift 1) JEE Main Previous Year Paper

Q12.The rms speed of oxygen molecule in a vessel at particular temperature is (1 + x 1 speed of the molecule. The value of x will be: (take π = 227 ) (1) 27 (2) 8 (3) 28 (4) 4

Q12.Heat energy of 184 kJ is given to ice of mass 600 g at −12 °C, Specific heat of ice is 2222. 3 J kg–1 °C–1 and latent heat of ice is 336 kJ kg–1 . (A) Final temperature of system will be 0 °C (B) Final temperature of the system will be greater than 0 °C (C) The final system will have a mixture of ice and water in the ratio of 5 : 1 (D) The final system will have a mixture of ice and water in the ratio of 1 : 5 (E) The final system will have water only Choose the correct answer from the options given below : JEE Main 2023 (29 Jan Shift 2) JEE Main Previous Year Paper (1) A and D only (2) B and D only (3) A and E only (4) A and C only times to that of its average speed in the gas. Then, the

Q12.An engine operating between the boiling and freezing points of water will have A. Efficiency more than 27% . B. Efficiency less than the efficiency of a Carnot engine operating between the same two temperatures. C. Efficiency equal to 27% . D. Efficiency less than 27% . Choose the correct answer from the options given below (1) B, C and D only (2) A and B only (3) B and D only (4) B and C only

Q12.A hypothetical gas expands adiabatically such that its volume changes from 08 litres to 27 litres. If the ratio of final pressure of the gas to initial pressure of the gas is 16 . Then the ratio of Cp will be. 81 Cv (1) 4 (2) 3 3 1 (3) 21 (4) 32

Q12.A Carnot engine with efficiency 50% takes heat from a source at 600 K . In order to increase the efficiency to 70% , keeping the temperature of sink same, the new temperature of the source will be: (1) 360 K (2) 1000 K (3) 900 K (4) 300 K

Q12.In the network shown below, the charge accumulated in the capacitor in steady state will be: (1) 10 . 3 𝜇C (2) 4 . 8 𝜇C (3) 12 𝜇C (4) 7 . 2𝜇C

Q12.The equivalent resistance of the circuit shown below between points 𝑎 and 𝑏 is : JEE Main 2023 (10 Apr Shift 1) JEE Main Previous Year Paper (1) 16 Ω (2) 3 . 2 Ω (3) 24 Ω (4) 20 Ω

Q12.The equivalent resistance between 𝐴 𝑎𝑛𝑑 𝐵 of the network shown in figure: 2𝑅 (1) 11 (2) 14 𝑅 3 (3) 21 𝑅 (4) 8 𝑅 3

Q12.For designing a voltmeter of range 50 V and an ammeter of range 10 mA using a galvanometer which has a coil of resistance 54 Ω showing a full scale deflection for 1 mA as in figure. (A) for voltmeter R ≈50 kΩ (B) for ammeter r ≈0. 2 Ω (C) for ammeter r ≈6 Ω (D) for voltmeter R ≈5 kΩ (E) for voltmeter R ≈500 Ω Choose the correct answer from the options given below: (1) (A) and (C) (2) (C) and (E) (3) (C) and (D) (4) (A) and (B)