Practice Questions

Q8. A monoatomic gas at pressure P and volume V is suddenly compressed to one eighth of its original volume. The final pressure at constant entropy will be (1) P (2) 8P (3) 32P (4) 64P

Q8. A radar sends an electromagnetic signal of electric field (E0) = 2. 25 V m−1 and magnetic field (B0) = 1. 5 × 10−8 T which strikes a target on line of sight at a distance of 3 km in a medium. After that, a part of signal (echo) reflects back towards the radar with same velocity and by same path. If the signal was transmitted at time t = 0 from radar, then after how much time echo will reach to the radar? (1) 2. 0 × 10−5 s (2) 4. 0 × 10−5 s (3) 1. 0 × 10−5s (4) 8. 0 × 10−5s

Q8. Two metallic blocks M1 and M2 of same area of cross-section are connected to each other (as shown in figure). If the thermal conductivity of M2 is K then the thermal conductivity of M1 will be : [Assume steady state heat conduction] JEE Main 2022 (24 Jun Shift 1) JEE Main Previous Year Paper (1) 10K (2) 8K (3) 12. 5K (4) 2K

Q8. In the figure, a very large plane sheet of positive charge is shown. 𝑃1 and 𝑃2 are two points at distance 𝑙 and 2𝑙 from the charge distribution. If 𝜎 is the surface charge density, then the magnitude of electric fields 𝐸1 and 𝐸2 at 𝑃1 and 𝑃2 respectively are JEE Main 2022 (25 Jun Shift 1) JEE Main Previous Year Paper 𝜎 𝜎 2𝜎 𝜎 (1) 𝐸1 = 𝜀𝑜, 𝐸2 = 2𝜀𝑜 (2) 𝐸1 = 𝜀𝑜, 𝐸2 = 𝜀𝑜 𝜎 𝜎 (3) 𝐸1 = 𝐸2 = (4) 𝐸1 = 𝐸2 = 2𝜀𝑜 𝜀𝑜

Q9. When a particle executes simple Harmonic motion, the nature of graph of velocity as function of displacement will be (1) Circular (2) Ellipitical (3) Sinusoidal (4) Straight line

Q9. In the wave equation 𝑦= 0 . 5sin 𝜆400𝑡- 𝑥𝑚 the velocity of the wave will be : (1) 200 m s-1 (2) 200√2 m s-1 (3) 400 m s-1 (4) 400√2 m s-1

Q9. For a perfect gas, two pressures P1 and P2 are shown in figure. The graph shows (1) P1 > P2 (2) P1 < P2 (3) P1 = P2 (4) Insufficient data to draw any conclusion

Q10.The displacement of simple harmonic oscillator after 3 seconds starting from its mean position is equal to half of its amplitude. The time period of harmonic motion is (1) 12 s (2) 8 s (3) 36 s (4) 6 s

Q10.A charge of 4μC is to be divided into two. The distance between the two divided charges is constant. The magnitude of the divided charges so that the force between them is maximum, will be: (1) 1μC and 3μC (2) 2μC and 2μC (3) 0 and 4μC (4) 1. 5μC and 2. 5μC

Q10.A long straight wire with a circular cross-section having radius 𝑅, is carrying a steady current 𝐼. The current 𝐼 is uniformly distributed across this cross-section. Then the variation of magnetic field due to current 𝐼 with distance 𝑟𝑟< 𝑅 from its centre will be (1) 𝐵∝𝑟 (2) 𝐵∝1 𝑟 1 (3) 𝐵∝𝑟2 (4) 𝐵∝ 𝑟2

Q10.A condenser of 2 𝜇F capacitance is charged steadily from 0 to 5 C. Which of the following graph represents correctly the variation of potential difference𝑉 across its plates with respect to the charge 𝑄 on the condenser? (1) (2) (3) (4)

Q11.An observer moves towards a stationary source of sound with a velocity one-fifth of the velocity of sound. The percentage change in the apparent frequency is (1) zero (2) 5% (3) 10% (4) 20%

Q11.Two point charges A and B of magnitude +8 × 10−6C and −8 × 10−6C respectively are placed at a distance d apart. The electric field at the middle point O between the charges is 6. 4 × 104 N C−1 . The distance ' d' between the point charges A and B is (1) 2 m (2) 3 m (3) 1 m (4) 4 m

Q11.The current I in the given circuit will be (1) 10A (2) 20A (3) 4A (4) 40A + T. If it has an acceleration of

Q12.If a wave gets refracted into a denser medium, then which of the following is true? (1) Wavelength, speed and frequency decreases. (2) Wavelength increases, speed decreases and frequency remains constant. (3) Wavelength and speed decreases but frequency (4) Wavelength, speed and frequency increases. remains constant.

Q12.A triangular shaped wire carrying 10 A current is placed in a uniform magnetic field of 0. 5 T, as shown in figure. The magnetic force on segment CD is (Given BC = CD = BD = 5 cm). (1) 0. 126 N (2) 0. 312 N (3) 0. 216 N (4) 0. 245 N

Q12.Given below are two statements. Statement I : Electric potential is constant within and at the surface of each conductor. Statement II : Electric field just outside a charged conductor is perpendicular to the surface of the conductor at every point. JEE Main 2022 (29 Jul Shift 1) JEE Main Previous Year Paper In the light of the above statements, choose the most appropriate answer from the options give below. (1) Both statement I and statement II are correct (2) Both statement I and statement II are incorrect (3) Statement I is correct but statement II is incorrect (4) Statement I is incorrect but and statement II is correct

Q12.If the electric potential at any point (x, y, z) m in space is given by V = 3x2 volt. The electric field at the point (1, 0, 3) m will be : (1) 3 Vm−1 , directed along positive x-axis. (2) 3 Vm−1 , directed along negative x-axis. (3) 6 Vm−1 , directed along negative x-axis. (4) 6 Vm−1 , directed along positive x-axis.

Q12.A parallel plate capacitor is formed by two plates each of area 30π cm2 separated by 1 mm. A material of dielectric strength 3. 6 × 107 V m−1 is filled between the plates. If the maximum charge that can be stored on the capacitor without causing any dielectric breakdown is 7 × 10−6 C, the value of dielectric constant of the material is : [Use 1 = 9 × 109 N m2 C−2 ] 4πεo (1) 1. 66 (2) 1. 75 (3) 2. 25 (4) 2. 33

Q12.The current sensitivity of a galvanometer can be increased by : (A) decreasing the number of turns (B) increasing the magnetic field (C) decreasing the area of the coil (D) decreasing the torsional constant of the spring Choose the most appropriate answer from the options given below : (1) (B) and (C) only (2) (C) and (D) only (3) (A) and (C) only (4) (B) and (D) only

Q12.The magnetic moment of an electron 𝑒 revolving in an orbit around nucleus with an orbital angular momentum is given by 𝑒𝐿 𝑒𝐿 - (1) →𝜇𝐿= 2 𝑚 (2) →𝜇𝐿= 2 𝑚 (3) 𝑒 →𝐿 (4) 2𝑒 →𝐿 - →𝜇𝐿= 𝑚 →𝜇𝐿= 𝑚

Q12.A long solenoid carrying a current produces a magnetic field 𝐵 along its axis. If the current is doubled and the number of turns per cm is halved, the new value of magnetic field will be equal to JEE Main 2022 (25 Jun Shift 2) JEE Main Previous Year Paper (1) 2𝐵 (2) 4𝐵 𝐵 (3) (4) 𝐵 2

Q12.If wattless current flows in the AC circuit, then the circuit is : (1) Purely Resistive circuit (2) Purely Inductive circuit (3) LCR series circuit (4) RC series circuit only 𝑡- 𝑥

Q12.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Alloys such as constantan and manganin are used in making standard resistance coils. Reason R: Constantan and manganin have very small value of temperature coefficient of resistance. In the light of the above statements, choose the correct answer from the options given below. (1) Both A and R are true and R is the correct (2) Both A and R are true but R is NOT the correct explanation of A explanation of A. (3) A is true but R is false. (4) A is false but R is true.

Q13.Two parallel, long wires are kept 0. 20 m apart in vacuum, each carrying current of x A in the same direction. If the force of attraction per meter of each wire is 2 × 10−6 N , then the value of x is approximately (1) 1 (2) 2. 4 (3) 1. 4 (4) 2