Practice Questions

Q82.Increasing order of stability among the three main conformations (i.e. Eclipse, Anti, Gauche) of 2- fluoroethanol is (1) Eclipse, Gauche, Anti (2) Gauche, Eclipse, Anti (3) Eclipse, Anti, Gauche (4) Anti, Gauche, Eclipse JEE Main 2006 JEE Main Previous Year Paper

Q83. The alkene formed as a major product in the above elimination reaction is (1) (2) CH2 = CH2 (3) (4)

Q86.The molar conductivities ∧∘NaOAC and ∧∘HCl at infinite dilution in water at 25∘C are 91.0 and 426.2 S cm2/mol respectively. To calculate ∧OHOAc , the additional value required is (1) ∧∘ (2) ∧∘KCl H2O (3) ∧∘NaOH (4) ∧∘NaCl

Q88.Resistance of a conductivity cell filled with a solution of an electrolyte of concentration 0.1M is 100Ω . The conductivity of this solution is 1.29 S m−1 . Resistance of the same cell when filled with 0.2M of the same solution is 520Ω . The molar conductivity of 0.02M solution of the electrolyte will be (1) 124 × 10−4 S m2 mol−1 (2) 1240 × 10−4 S m2 mol−1 (3) 1.24 × 10−4 S m2 mol−1 (4) 12.4 × 10−4 S m2 mol−1 JEE Main 2006 JEE Main Previous Year Paper

Q92.In Langmuir’s model of adsorption of a gas on a solid surface (1) the rate of dissociation of adsorbed molecules (2) the adsorption at a single site on the surface may from the surface does not depend on the surface involve multiple molecules at the same time covered (3) the mass of gas striking a given area of surface is (4) the mass of gas striking a given area of surface is proportional to the pressure of the gas independent of the pressure of the gas

Q93.Which of the following chemical reactions depicts the oxidizing behaviour of H2SO4 ? (1) 2HI + H2SO4 ⟶I2 + SO2 + 2H2O (2) Ca(OH)2 + H2SO4 ⟶CaSO4 + 2H2O (3) NaCl + H2SO4 ⟶NaHSO4 + HCl (4) 2PCl5 + H2SO4 ⟶2POCl3 + 2HCl + SO2Cl2

Q94.What products are expected from the disproportionation reaction of hypochlorous acid? (1) HClO3 and Cl2O (2) HClO2 and HClO4 (3) HCl and Cl2O (4) HCl and HClO3

Q96.The IUPAC name for the complex [Co (NO2)(NH3)5]Cl2 is JEE Main 2006 JEE Main Previous Year Paper (1) nitrito-N-pentaamminecobalt (III) chloride (2) nitrito-N-pentaamminecobalt (II) chloride (3) pentaammine nitrito- N -cobalt (II) chloride (4) pentaammine nitrito- N -cobalt (III) chloride

Q98.In Fe(CO)5 , the Fe −C bond possesses (1) π-character only (2) both σ and π characters (3) ionic character (4) σ-character only

Q1. A particle is moving eastwards with a velocity of 5 m/s in 10 seconds the velocity changes to 5 m/s northwards. The average acceleration in this time is (1) 1 m/s2 towards north-east (2) 21 m/s2 towards north. √2 (3) zero (4) 1 m/s2 towards north-west √2

Q3. The relation between time t and distance x is t = ax2 + bx where a and b are constants. The acceleration is (1) −2abv2 (2) 2bv3 (3) −2av3 (4) 2av2

Q4. A car starting from rest accelerates at the rate f through a distance S , then continues at constant speed for time t and then decelerates at the rate f/2 to come to rest. If the total distance traversed is 15 S, then (1) S = ft (2) S = 1/6ft2 (3) S = 1/2ft2 (4) None of these

Q5. A parachutist after bailing out falls 50 m without friction. When parachute opens, it decelerates at 2 m/s2 . He reaches the ground with a speed of 3 m/s. At what height, did he bail out? (1) 91 m (2) 182 m (3) 293 m (4) 111 m

Q8. A projectile can have the same range R for two angles of projection. If t1 and t2 be the times of flights in the two cases, then the product of the two time of flights is proportional to (1) R2 (2) 1/R2 (3) 1/R (4) R

Q10.A smooth block is released at rest on a 45∘ incline and then slides a distance d. The time taken to slide is n times as much to slide on rough incline than on a smooth incline. The coefficient of friction is JEE Main 2005 JEE Main Previous Year Paper 1 − n2 (1) μk = 1 − n21 (2) μk = √1 1 − n2 (3) μs = 1 − n21 (4) μs = √1

Q12.A block is kept on a frictionless inclined surface with angle of inclination α. The incline is given an acceleration a to keep the block stationary. Then a is equal to (1) g/ tan α (2) g cosec α (3) g (4) g tan α

Q14.Consider a car moving on a straight road with a speed of 100 m/s. The distance at which car can be stopped is [μk = 0.5] (1) 800 m (2) 1000 m (3) 100 m (4) 400 m

Q15.An annular ring with inner and outer radii R1 and R2 is rolling without slipping with a uniform angular speed. The ratio of the forces experienced by the two particles situated on the inner and outer parts of the ring, F1/F2 is (1) R2 (2) R1 2 R1 ( R2 ) (3) 1 (4) R1 R2

Q16.A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm. How much further it will penetrate before coming to rest assuming that it faces constant resistance to motion? (1) 3.0 cm (2) 2.0 cm (3) 1.5 cm (4) 1.0 cm

Q18.A body of mass m is accelerated uniformly from rest to a speed v in a time T . The instantaneous power delivered to the body as a function time is given by (1) mv2 ⋅t (2) mv2 ⋅t2 T 2 T2 1 mv2 (3) 2 T2 ⋅t (4) 21 mv2T2 ⋅t2

Q20.The block of mass M moving on the frictionless horizontal surface collides with a spring of spring constant K and compresses it by length L. The maximum momentum of the block after collision is (1) √MKL (2) KL2 2M (3) zero (4) ML2 K

Q21.A mass ' m ' moves with a velocity v and collides inelastically with another identical mass. After collision the 1st mass moves with velocity v/√3 in a direction perpendicular to the initial direction of motion. Find the speed of the 2nd mass after collision (1) v (2) √3v (3) 2v/√3 (4) v/√3

Q22.The moment of inertia of a uniform semicircular disc of mass M and radius r about a line perpendicular to the plane of the disc through the centre is (1) 4 1 Mr2 (2) 25 Mr2 (3) Mr2 (4) 12 Mr2

Q25.The change in the value of g at a height ' h ' above the surface of the earth is the same as at a depth 'd' below the surface of earth. When both ' d ' and ' h ' are much smaller than the radius of earth, then which one of the following is correct? (1) d = h2 (2) d = 32h (3) d = 2 h (4) d = h

Q26.A particle of mass 10 g is kept on the surface of a uniform sphere of mass 100 kg and radius 10 cm. Find the work to be done against the gravitational force between them to take the particle far away from the sphere (you may take G = 6.67 × 10−11Nm2/kg2 ) (1) 13.34 × 10−10 J (2) 3.33 × 10−10 J (3) 6.67 × 10−9 J (4) 6.67 × 10−10 J