Vr's JEE Mock Test -1

Hysteresis loops for two magnetic materials A and B are given below : These materials are used to make magnets for electric generators, transformer core and electromagnet core. Then it is proper to use ;

• B for electromagnets and transformers.

• A for electric generators and transformers.

• A for electromagnets and B for electric transformers.

• A for transformers and B for electric generators

 A student measures the time period of 100 oscillations of a simple pendulum four times. The datasetis90s,91s,95sand92s.Iftheminimum division in the measuring clock is 1 s, then the reported mean time should be :-

• 92 ± 3 s

• 92 ± 2 s

• 92 ± 5 s

• 92 ± 1.8 s

The IUPAC name of the coordination compound K3[Fe(CN)6] is

• Potassium hexacyanoferrate (II)

• Potassium hexacyanoferrate (III)

• Potassium hexacyanoiron (II)

• Tripotassium hexcyanoiron (II)

Which base is present in RNA but not in DNA?

• Uracil

• Thymine

• Guanine

• Cytosine

The synthesis of alkyl fluorides is best accomplished by :

• Free radical fluorination

• Sandmeyer’s reaction

• Finkelstein reaction

• Swarts reaction

Identify the correct statement regarding a spontaneous process

• For a spontaneous process in an isolated system, the change in entropy is positive

• Endothermic processes are never spontaneous

• Exothermic processes are always spontaneous

• Lowering of energy in the reaction process is the only criterion for spontaneity

Which one of the following conformation of cyclohexane is chiral?

• Twist boat

• Rigid

• Boat

• Chair

Which of the following compounds will exhibit geometrical isomerism 

• 1-Phenyl-2-butene

• 3-Phenyl-1-butene

• 2 - Phenyl -1-butene

• 1, 1 - Diphenyl -1 - propane

An ionic compound has a unit cell consisting of A ions at the corners of a cube and B ions on the centres of the faces of the cube. The empirical formula for this compound would be

• AB

• AB2

• A2B3

• AB3

Hydrogen bomb is based on the principle of

• Nuclear fission

• Natural radioactivity

• Nuclear fusion

• Artificial radioactivity

During the process of electrolytic refining of settle as ‘anode mud’ These are

• Sn and Ag

• Pb and Zn

• Ag and Au

• Fe and Ni

If the 2nd, 5th and 9th terms of a non-constant A.P. are in G.P., then the common ratio of this G.P. is 

• 7/4

• 4/3

• 1

• 8/5

If two different numbers are taken from the set {0, 1, 2, 3, ......., 10), then the probability that their sum as well as absolute difference are both multiple of 4, is :-

• 7/55

• 6/55

• 12/55

• 14/45

• 1/4

• 1/8

• 1/16

• 1/24

• -1

• -2

• 2

• 4

• 13

• -1

• 5

• 4

If (2, 3, 5) is one end of a diameter of the sphere x2 + y2 + z2 − 6x − 12y − 2z + 20 = 0, then the coordinates of the other end of the diameter are

• (4, 9, −3)

• (4, −3, 3)

• (4, 3, 5)

• (4, 3, −3)

If the roots of the quadratic equation x2 + px + q = 0 are tan30° and tan15°, respectively then the value of 2 + q − p is

• 2

• 3

• 0

• 1

Let W denote the words in the English dictionary. Define the relation R by : R = {(x, y) ∈ W × W | the words x and y have at least one letter in common}. Then R is

• Not reflexive, symmetric and transitive

• Reflexive, symmetric and not transitive

• Reflexive, symmetric and transitive

• Reflexive, not symmetric and transitive

A man is walking towards a vertical pillar in a straight path, at a uniform speed. At a certain point A on the path, he observes that the angle of elevation of the top of the pillar is 30°. After walking for 10 minutes from A in the same direction, at a point B, he observes that the angle of elevation of the top of the pillar is 60°. Then the time taken (in minutes) by him, form B to reach the pillar, is :

• 5

• 6

• 10

• 20

Conjugate of the complex number 3 – 2i is

• 2+3i

• 3+2i

• 2–3i

• 3–2i

Let P be the point on the parabola, y2 = 8x which is at a minimum distance from the cente C of the circle, x2 + (y + 6)2 = 1. Then the equation of the circle, passing through C and having its centre at P is :

• X2 + y2 – 4x + 9y + 18 = 0

• X2 + y2 – 4x + 8y + 12 = 0

• X2+y2–x+4y–12=0

• X2+y2–x+4y+12=0

The mean of the data set comprising of 16 observations is 16. If one of the observation valued 16 is deleted and three new observations valued 3, 4 and 5 are added to the data, then the mean of the resultant data, is 

• 16.8

• 16

• 14

• 15.8

Thenumberofcommontangentstothecirclesx2 +y2 4x6y12=0andx2 +y2 +6x+18y + 26 = 0, is :

• 1

• 2

• 3

• 4

The area (in sq. units) of the quadrilateral formed by the tangents at the end points of the latera recta to the ellipse x²/9+ y²/5 =1 

• 27

• 18

• 27/2

• 27/4

If one of the diameters of the circle, given by the euqation,x2 +y2 –4x+6y–12=0,isachord of a circle S, whose centre is at (–3, 2), then the radius of S is :-

• 5

• 5*2^1/2

• 5*2^1/3

• 10

The number of integers greater than 6,000 that can be formed, using the digits 3, 5, 6, 7 and 8, without repetition, is :

• 216

• 72

• 192

• 160

Choose the line which is perpendicular to x – 3y + 7 = 0

• 3x+y+1=0

• 3x-y+2=0

• X+3y+7=0

• X–3y+8 =0

Ifn(A)=3,n(B)=4 n(AxB)equals

• 7

• 8

• 12

• 32

A reaction involving two different reactants can never be

• Unimolecular reaction

• First order reaction

• Second order reaction

• Bimolecular reaction

A potentiometer is an accurate and versatile device to make electrical measurements of E.M.F, because the method involves :

• Cells

• Potential gradients

• A condition of no current flow through the galvanometer

• A combination of cells, galvanometer and resistances

Two lenses of power -15 D and + 5D are in contact with each other. The focal length of the combination is

• −20 cm

• + 20 cm

• −10 cm

• + 10 cm

The group having isoelectronic species is

• O2– , F –, Na+ , Mg2+

• O– , F –, Na , Mg+

• O2– , F –, Na , Mg2+

• O– , F –, Na + , Mg+

Which of the following compounds is not an antacid?

• Aluminium hydroxide

• Cimetidine

• Ranitidine

• Phenelzine

A current of 2.5 A flows through a coil of inductance 5 H. The magnetic flux linked with the coil is

• 2 Wb

• 0.5 Wb

• ZERO

• 12.5 Wb

If nεN, 7n -3n is always divisible by

• 10

• 7

• 4

• 3

The rate equation for the reaction 2A + B → C is found to be: rate k[A][B]. The correct statement in relation to this reaction is that the

• Unit of K must be s-1

• Values of k is independent of the initial concentration of A and B

• Rate of formation of C is twice the rate of disappearance of A

• T1/2 is a constant

The binding energy per nucleon for the parent nucleus is E1 and that for the daughter nuclei is E2. Then

• E2 =2E1

• E1 >E2

• E2 > E1

• E1 =2E2

What is the minimum energy required to launch a satellite of mass m from the surface of a planet of mass M and radius R in a circular orbit at an altitude of 2R? 

• 2GmM /3R

• GmM /3R

• 5GmM /6R

• GmM /2R

Based on lattice energy and other considerations which one of the following alkali metal chlorides is expected to have the highest melting point.

• LiCl

• NaCl

• RbCl

• KCl

The most abundant elements by mass in the body of a healthy human adult are : Oxygen (61.4%) ; Carbon (22.9%), Hydrogen (10.0%) ; and Nitrogen (2.6%). The weight which a 75 kg person would gain if all 1H atoms are replaced by 2H atoms is

• 15 Kg

• 7.5 Kg

• 37.5 Kg

• 10 Kg

A mass ‘m’ is supported by a massless string wound around a uniform hollow cylinder of mass m and radius R. If the string does not slip on the cylinder, with what acceleration will the mass fall on release?

• 5g/6

• 2g/3

• G/2

• G

One way in which the operation of a n-p-n transistor differs from that of a p-n-p

• The emitter junction is reversed biased in n-p-n

• The emitter junction injects minority carriers into the base region of the p-n-p

• The emitter injects holes into the base of the p-n-p and electrons into the base region of n-p-n

• The emitter injects holes into the base of n-p-n

Which of the following atoms has the highest first ionization energy ?

• Na

• Sc

• Rb

• K

In the Hofmann bromamide degradation reaction, the number of moles of NaOH and Br2 used per mole of amine produced are :

• Four moles of NaOH and one mole of Br2

• One mole of NaOH and one mole of Br2

• Four moles of NaOH and two moles of Br2

• Two moles of NaOH and two moles of Br2

Galvanization is applying a coating of 

• Pb

• Cr

• Zn

• Cu

Which of the following is the energy of a possible excited state of hydrogen?

• +13.6 eV

• + 6.8 eV

• - 6.8 eV

• - 3.4 eV

A box contains 15 green and 10 yellow balls. If 10 balls are randomly drawn, one–by–one, with replacement, then the variance of the number of green balls drawn is 

• 6/25

• 12/5

• 4

• 6