Practice Questions

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)

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 graph between two temperature scales P and Q is shown in the figure. Between upper fixed point and lower fixed point there are 150 equal divisions of scale P and 100 divisions on scale Q. The relationship for conversion between the two scales is given by : . JEE Main 2023 (25 Jan Shift 2) JEE Main Previous Year Paper tQ (1) 150 = tP−180100 (2) 100tQ = tP−30150 (3) 180 tP = tQ−40100 (4) 100tQ = tP−180150

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.A long straight wire of circular cross-section (radius 𝑎) is carrying steady current I . The current I is uniformly distributed across this cross-section. The magnetic field is (1) inversely proportional to 𝑟 in the region 𝑟< 𝑎 (2) directly proportional to 𝑟 in the region 𝑟< 𝑎 and and uniform throughout in the region 𝑟> 𝑎 inversely proportional to 𝑟 in the region 𝑟> 𝑎 (3) Zero in the region 𝑟< 𝑎 and inversely (4) uniform in the region 𝑟< 𝑎 and inversely proportional to 𝑟 in the region 𝑟> 𝑎 proportional to distance 𝑟 from the axis, in the region 𝑟> 𝑎

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.The charge flowing in a conductor changes with time as 𝑄𝑡= 𝛼𝑡- 𝛽𝑡2 + 𝛾𝑡3, where 𝛼, 𝛽 and 𝛾 are constants. Minimum value of current is: (1) 3𝛽2 (2) 𝛾2 𝛼- 𝛼- 𝛾 3𝛽 (3) 𝛽- 𝛼2 (4) 𝛼- 𝛽2 3𝛾 3𝛾

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.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.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.The root mean square speed of molecules of nitrogen gas at 27°C is approximately: (Given mass of a nitrogen molecule = 4. 6 × 10−26 kg and take Boltzmann constant kB = 1. 4 × 10−23J K−1 ) (1) 27. 4 m s−1 (2) 91 m s−1 (3) 1260 m s−1 (4) 523 m s−1

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.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 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.An air bubble of diameter 6 mm rises steadily through a solution of density 1750 kg m−3 at the rate of 0. 35 cm s−1 . The co-efficient of viscosity of the solution (neglect density of air) is ________ Pas (given, g = 10 m s−2 ).

Q13.A bar magnet with a magnetic moment 5 . 0 A m2 is placed in parallel position relative to a magnetic field of 0 . 4 T. The amount of required work done in turning the magnet form parallel to antiparallel position relative to the field direction is ________. (1) 4 J (2) 1 J (3) 2 J (4) Zero

Q13.For a simple harmonic motion in a mass spring system shown, the surface is frictionless. When the mass of the block is 1 kg, the angular frequency is ω1 . When the mass block is 2 kg the angular frequency is ω2 . The ratio JEE Main 2023 (30 Jan Shift 2) JEE Main Previous Year Paper ω2 is : ω1 (1) √2 (2) 1 √2 (3) 2 (4) 12

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.A simple pendulum with length 100 cm and bob of mass 250 g is executing S.H.M of amplitude 10 cm. The maximum tension in the string is found to be x N . The value of x is _____. 40

Q13.The current sensitivity of moving coil galvanometer is increased by 25%. This increase is achieved only changing in the number of turns of coils and area of cross section of the wire while keeping the resistance of galvanometer coil constant. The percentage change in the voltage sensitivity will be: (1) +25% (2) -50% (3) -25% (4) Zero

Q13.Given below are two statements: Statement I: For diamagnetic substance -1 ≤x < 0, where x is the magnetic susceptibility. Statement II: Diamagnetic substance when placed in an external magnetic field, tend to move from stronger to weaker part of the field. In the light of the above statements, choose the correct answer from the options give below. (1) Both Statement I and Statement II are False (2) Statement I is correct but Statement II is false (3) Statement I is incorrect but Statement II is true (4) Both Statement I and Statement II are true

Q13.Given below are two statements: Statement I: If the number of turns in the coil of a moving coil galvanometer is doubled then the current sensitivity becomes double. Statement II: Increasing current sensitivity of a moving coil galvanometer by only increasing the number of turns in the coil will also increase its voltage sensitivity in the same ratio 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) Statement I is false but Statement II is true (3) Both Statement I and Statement II are false (4) Both Statement I and Statement II are true

Q13.Let γ1 be the ratio of molar specific heat at constant pressure and molar specific heat at constant volume of a monoatomic gas and γ2 be the similar ratio of diatomic gas. Considering the diatomic gas molecule as a rigid rotator, the ratio γ1 is: γ2 (1) 27 (2) 35 35 27 (3) 25 (4) 21 21 25

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