Practice Questions

Q20.At a particular station, the TV transmission tower has a height of 100 m. To triple its coverage range, height of the tower should be increased to (1) 200 m (2) 300 m (3) 600 m (4) 900 m

Q20.In the circuit, the logical value of 𝐴= 1 or 𝐵= 1 when potential at 𝐴 or 𝐵 is 5 V and the logical value of 𝐴= 0 or 𝐵= 0 when potential at 𝐴 or 𝐵 is 0V. The truth table of the given circuit will be : (1) 𝐴 𝐵𝑌 (2) 𝐴 𝐵𝑌 0 0 0 0 0 0 1 0 0 1 0 1 0 1 0 0 1 1 1 1 1 1 1 1 (3) 𝐴 𝐵𝑌 (4) 𝐴 𝐵𝑌 0 0 0 0 0 1 1 0 0 1 0 1 0 1 0 0 1 1 1 1 0 1 1 0

Q20.Amplitude modulated wave is represented by VAM = 10[1 + 0. 4 cos(2π × 104t)] cos(2π × 107t). The total bandwidth of the amplitude modulated wave is (1) 10 kHz (2) 20 MHz (3) 20 kHz (4) 10 MHz

Q20.We do not transmit low frequency signal to long distances because (a) The size of the antenna should be comparable to signal wavelength which is unreal solution for a signal of longer wavelength. (b) Effective power radiated by a long wavelength baseband signal would be high. (c) We want to avoid mixing up signals transmitted by different transmitter simultaneously. (d) Low frequency signal can be sent to long distances by superimposing with a high frequency wave as well. Therefore, the most suitable option will be : (1) All statements are true (2) (a), (b) and (c) are true only (3) (a), (c) and (d) are true only (4) (b), (c) and (d) are true only

Q20.In Bohr's atomic model of hydrogen, let K, P and E are the kinetic energy, potential energy and total energy of the electron respectively. Choose the correct option when the electron undergoes transitions to a higher level : (1) All K, P and E increase. (2) K decreases, P and E increase. (3) P decreases, K and E increase. (4) K increases, P and E decrease

Q20.A square wave of the modulating signal is shown in the figure. The carrier wave is given by C(t) = 5 sin(8πt) Volt. The modulation index is (1) 0. 2 (2) 0. 1 (3) 0. 3 (4) 0. 4

Q20.In an experiment to find out the diameter of wire using screw gauge, the following observation were noted: (a) Screw moves 0. 5 mm on main scale in one complete rotation (b) Total divisions on circular scale = 50 (c) Main scale reading is 2. 5 mm (d) 45th division of circular scale is in the pitch line (e) Instrument has 0. 03 mm negative error Then the diameter of wire is : (1) 2. 92 mm (2) 2. 54 mm (3) 2. 98 mm (4) 3. 45 mm

Q21.A ball is projected vertically upward with an initial velocity of 50 m s−1 at t = 0 s. At t = 2 s, another ball is projected vertically upward with same velocity. At t =____ s, second ball will meet the first ball (g = 10 m s−2) .

Q21.The moment of inertia of a uniform thin rod about a perpendicular axis passing through one end is I1 . The x same rod is bent into a ring and its moment of inertia about a diameter is I2 . If I2I1 is xπ23 , then the value of will be ______.

Q21.From the top of a tower, a ball is thrown vertically upward which reaches the ground in 6 s. A second ball thrown vertically downward from the same position with the same speed reaches the ground in 1. 5 s. A third JEE Main 2022 (24 Jun Shift 1) JEE Main Previous Year Paper ball released, from the rest from the same location, will reach the ground in _____ s.

Q21.In an experiment to find acceleration due to gravity (g) using simple pendulum, time period of 0. 5 s is measured from time of 100 oscillation with a watch of 1 s resolution. If measured value of length is 10 cm known to 1 mm accuracy. The accuracy in the determination of g is found to be x%. The value of x is

Q21.Two inclined planes are placed as shown in figure. A block is projected from the Point A of inclined plane AB along its surface with a velocity just sufficient to carry it to the top Point B at a height 10 m. After reaching the Point B the block slides down on inclined plane + BC . Time it takes to reach to the point C from point A is t(√2 1)s. The value of t is _____ (use g = 10 m s−2 )

Q21.A ball of mass 0. 5 kg is dropped from the height of 10 m . The height, at which the magnitude of velocity becomes equal to the magnitude of acceleration due to gravity, is _____ m. [Use g = 10 m s−2 ]

Q21.A hanging mass M is connected to a four times bigger mass by using a string pulley arrangement, as shown in the figure. The bigger mass is placed on a horizontal ice-slab and being pulled by 2 Mg force. In this situation, tension in the string is x 5 Mg for x =_____. Neglect mass of the string and friction of the block (bigger mass) with ice slab. (Given g = acceleration due to gravity)

Q21.If the projection of 2 ^𝑖+ 4 ^𝑗- 2 ^𝑘 on ^𝑖+ 2 ^𝑗+ 𝛼 ^𝑘 is zero. Then, the value of 𝛼 will be

Q21.In an experiment of determine the Young's modulus of wire of a length exactly 1 m, the extension in the length of the wire is measured as 0. 4 mm with an uncertainty of ±0. 02 mm when a load of 1 kg is applied. The JEE Main 2022 (26 Jul Shift 1) JEE Main Previous Year Paper diameter of the wire is measured as 0. 4 mm with an uncertainty of ±0. 01 mm. The error in the measurement of Young's modulus (ΔY) is found to be x × 1010 N m−2 . The value of x is _____ .

Q21.If →𝐴= 2 ^i + 3 ^j - ^k m and →𝐵= ^i + 2 ^j + 2 ^k m. The magnitude of component of vector →𝐴 along vector →𝐵 will be _____ m.

Q21.For 𝑧= 𝑎2𝑥3𝑦 12, where '𝑎' is a constant. If percentage error in measurement of '𝑥' and '𝑦' are 4%and 12%, respectively, then the percentage error for '𝑧' will be _____ % .

Q21.A tube of length 50 cm is filled completely with an incompressible liquid of mass 250 g and closed at both ends. The tube is then rotated in horizontal plane about one of its ends with a uniform angular velocity 𝑥√𝐹 rad s-1. If 𝐹 be the force exerted by the liquid at the other end then the value of 𝑥 will be _____ .

Q21.A mass of 10 kg is suspended vertically by a rope of length 5 m from the roof. A force of 30 N is applied at the middle point of rope in horizontal direction. The angle made by upper half of the rope with vertical is α = tan−1(x × 10−1). The value of x is _____ . (Given, g = 10 m s−2 ) JEE Main 2022 (27 Jun Shift 2) JEE Main Previous Year Paper

Q21.A uniform chain of 6 m length is placed on a table such that a part of its length is hanging over the edge of the table. The system is at rest. The co-efficient of static friction between the chain and the surface of the table is 0 . 5, the maximum length of the chain hanging from the table is _____ m.

Q21.As per the given figure, two plates A and B of thermal conductivity K and 2K are joined together to form a compound plate. The thickness of plates are 4. 0 cm and 2. 5 cm respectively and the area of cross-section is 120 cm2 for each plate. The equivalent thermal conductivity of the compound plate is (1 + α5 )K , then the value of α will be _____ . Q22. 300 calories of heat is given to a heat engine, and it rejects 225 calories of heat. If source temperature is 227°C, then the temperature of sink will be _____ ∘C.

Q21.A particle is moving in a straight line such that its velocity is increasing at 5 m s−1 per meter. The acceleration of the particle is _____ m s−2 at a point where its velocity is 20 m s−1 .

Q21.A car covers AB distance with first one-third at velocity v1 m s−1 , second one-third at v2 m s−1 and last one- third at v3 m s−1 . If v3 = 3v1, v2 = 2v1 and v1 = 11 m s−1 , then the average velocity of the car is _____ m s−1 .

Q21.A ball of mass m is thrown vertically upward. Another ball of mass 2 m is thrown an angle θ with the vertical. Both the balls stay in air for the same period of time. The ratio of the heights attained by the two balls respectively is 1 . The value of x is _____ . x