Practice Questions

Q59.In the given reaction the number of sp2 hybridised carbon (s) in compound ′X′ is _______.

Q59.The oxidation state of manganese in the product obtained in a reaction of potassium permanganate and hydrogen peroxide in basic medium is

Q59.For a first order reaction A →B, the rate constant, k = 5. 5 × 10−14 s−1 . The time required for 67% completion of reaction is x × 10−1 times the half life of reaction. The value of x is Nearest integer) (Given : log 3 = 0. 4771 )

Q59.The difference in oxidation state of chromium in chromate and dichromate salts is___

Q60.The number of chlorine atoms in bithionol is 1

Q60. In alanylglycylleucylalanylvaline the number of peptide linkages is:

Q60.The number of oxygen present in a nucleotide formed from a base, that is present only in RNA is

Q60.The spin only magnetic moment of the complex present in Fehling's reagent is____ B. M. (Round off your answer to the nearest integer) 1 2 5 5) 3 3) 3 + −5(log5 = 0 then

Q61.The minimum value of the sum of the squares of the roots of 𝑥2 + 3 - 𝑎𝑥= 2𝑎- 1 is (1) 6 (2) 4 (3) 5 (4) 8

Q61.Let the minimum value v0 of v = |z|2 + |z −3|2 + |z −6i|2 , z ∈C is attained at z = z0 . Then ¯2z20 −z30 + 3 2 + v20 is equal to (1) 1000 (2) 1024 (3) 1105 (4) 1196

Q81.Let S = {z ∈C : z2 + z = 0}. Then ∑z∈S(Re (z)+ Im (z)) is equal to _______.

Q82.A class contains b boys and g girls. If the number of ways of selecting 3 boys and 2 girls from the class is 168 , then b + 3g is equal to

Q90.The sum and product of the mean and variance of a binomial distribution are 82 . 5 and 1350 respectively. They the number of trials in the binomial distribution is JEE Main 2022 (29 Jul Shift 2) JEE Main Previous Year Paper

Q20.In amplitude modulation, the message signal 𝑉m ( 𝑡) = 10sin2𝜋× 105𝑡 volts and carrier signal 𝑉C𝑡= 20sin2𝜋× 107𝑡 volts. The modulated signal now contains the message signal with lower side band and upper side band frequency, therefore the bandwidth of modulated signal is 𝛼 kHz. The value of 𝛼 is: (1) 200 kHz (2) 500 kHz (3) 100 kHz (4) 0

Q21.If P × Q = Q × P , the angle between P and Q is θ(0°< θ < 360°). The value of θ will be ___ ° .

Q21.Two solids A and B of mass 1 kg and 2 kg respectively are moving with equal linear momentum. The ratio of their kinetic energies (K. E. )A : (K. E. )B will be A1 , so the value of A will be _________.

Q21.If the velocity of a body related to displacement x is given by v = √5000 + 24x m s−1, then the acceleration of the body is _________ m s−2.

Q21.The resistance R = VI , where V = (50 ± 2) V and I = (20 ± 0. 2) A . The percentage error in R is x % . The value of x to the nearest integer is ________.

Q21.A boy pushes a box of mass 2 kg with a force F = (20ˆi 10ˆj)N on a frictionless surface. If the box was initially at rest, then _______ m is displacement along the x -axis after 10 s JEE Main 2021 (26 Feb Shift 1) JEE Main Previous Year Paper

Q22.A solid disc of radius 20 cm and mass 10 kg is rotating with an angular velocity of 600 rpm, about an axis normal to its circular plane and passing through its centre of mass. The retarding torque required to bring the disc at rest in 10 s is _________ π × 10−1 N m

Q22.A person standing on a spring balance inside a stationary lift measures 60 kg . The weight of that person if the lift descends with uniform downward acceleration of 1. 8 m s−2 will be N. [g = 10 m s−2]

Q22.A bullet of mass 0. 1 kg is fired on a wooden block to pierce through it, but it stops after moving a distance of 50 cm into it. If the velocity of the bullet before hitting the wood is 10 m s−1 and, it slows down with uniform deceleration, then the magnitude of effective retarding force on the bullet is x N. The value of x to the nearest integer is,

Q22.Two persons A and B perform same amount of work in moving a body through a certain distance d with application of forces acting at angles 45° and 60° with the direction of displacement respectively. The ratio of force applied by person A to the force applied by person B is 1 . The value of x is _________. √x

Q22.The angular speed of truck wheel is increased from 900 rpm to 2460 rpm in 26 seconds. The number of revolutions by the truck engine during this time is ______. (Assuming the acceleration to be uniform).

Q22.Two particles having masses 4 g and 16 g respectively are moving with equal kinetic energies. The ratio of the magnitudes of their linear momentum is n : 2 . The value of n will be ___.