Practice Questions

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.A spherical drop of liquid splits into 1000 identical spherical drops. If ui is the surface energy of the original = ( 10x ). Then drop and uf is the total surface energy of the resulting drops, the (ignoring evaporation), ufui value of x is ______:

Q10.The distance between two plates of a capacitor is 𝑑 and its capacitance is 𝐶1, when air is the medium between 2𝑑 the plates. If a metal sheet of thickness and of the same area as plate is introduced between the plates, the 3 𝐶2 capacitance of the capacitor becomes 𝐶2 . The ratio is 𝐶1 (1) 3 : 1 (2) 2 : 1 (3) 4 : 1 (4) 1 : 1

Q10.In a linear Simple Harmonic Motion (SHM) (A) Restoring force is directly proportional to the displacement. (B) The acceleration and displacement are opposite in direction. (C) The velocity is maximum at mean position. (D) The acceleration is minimum at extreme points. Choose the correct answer from the options given below: (1) (C) and (D) only (2) (A), (C) and (D) only (3) (A), (B) and (C) only (4) (A), (B) and (D) only

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.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.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

Q10.The surface tension of soap solution is 3. 5 × 10−2 N m−1 . The amount of work done required to increase the radius of soap bubble from 10 cm to 20 cm is _____ ×10−4 J . (take π = 227 )

Q10.Glycerin of density 1. 25 × 103 kg m–3 is flowing through the conical section of pipe. The area of cross- section of the pipe at its ends are 10 cm2 and 5 cm2 and pressure drop across its length is 3 N m–2 . The rate of flow of glycerine through the pipe is x × 10–5 m3 s–1 . The value of x is _____.

Q10.The elastic potential energy stored in a steel wire of length 20 m stretched through 2 cm is 80 J. The cross sectional area of the wire is _____ mm2. (Given, Y = 2. 0 × 1011 N m–2 )

Q10.A water heater of power 2000 W is used to heat water. The specific heat capacity of water is 4200 J kg−1 K−1 . The efficiency of heater is 70%. Time required to heat 2 kg of water from 10°C to 60°C is _____ s . (Assume that the specific heat capacity of water remains constant over the temperature range of the water).

Q10.An aluminium rod with Young’s modulus Y = 7. 0 × 1010 N m−2 undergoes elastic strain of 0. 04%. The energy per unit volume stored in the rod in SI unit JEE Main 2023 (08 Apr Shift 1) JEE Main Previous Year Paper (1) 2800 (2) 11200 (3) 5600 (4) 8400

Q10.A fully loaded boeing aircraft has a mass of 5. 4 × 105 kg. Its total wing area is 500 m2 . It is in level flight with a speed of 1080 km h−1 . If the density of air ρ is 1. 2 kg m–3 , the fractional increase in the speed of the air on the upper surface of the wing relative to the lower surface in percentage will be ( g = 10 m s−2 ) (1) 16 (2) 6 (3) 8 (4) 10

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

Q10.As shown in the figure, in an experiment to determine Young's modulus of a wire, the extension-load curve is plotted. The curve is a straight line passing through the origin and makes an angle of 45° with the load axis. The length of wire is 62. 8 cm and its diameter is 4 mm. The Young's modulus is found to be x × 104 N m−2 The value of x is _______.

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.A body cools from 60°C to 40°C in 6 minutes. If, temperature of surroundings is 10°C . Then, after the next 6 minutes, its temperature will be ______ °C.

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 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.The maximum potential energy of a block executing simple harmonic motion is 25 J. A is amplitude of 𝐴 oscillation. At 2, the kinetic energy of the block is (1) 37 . 5 J (2) 9 . 75 J (3) 18 . 75 J (4) 12 . 5 J

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

Q11.A body cools from 80oC to 60o in 5 minutes. The temperature for the surrounding is 20oC. The time it takes to cool from 60oC to 40oC is (1) 450 s (2) 420 s (3) 500 s (4) 253 s

Q11.Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Efficiency of a reversible heat engine will be highest at –273 °C temperature of cold reservoir. Reason R : The efficiency of Carnot’s engine depends not only on temperature of cold reservoir but it depends on the temperature of hot reservoir too and is given as η = (1 −T2T1 ) In the light of the above statements, choose the correct answer from the options given below : (1) A is true but R is false (2) Both A and R are true but R is NOT the correct explanation of A (3) A is false but R is true (4) Both A and R are true and R is the correct explanation of A

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 parallel plate capacitor of capacitance 2 F is charged to a potential 𝑉. The energy stored in the capacitor is 𝐸1. The capacitor is now connected to another uncharged identical capacitor in parallel combination. The 𝐸2 energy stored in the combination is 𝐸2. The ratio is 𝐸1 (1) 2: 1 (2) 2: 3 (3) 1: 2 (4) 1: 4