KEAM Paper 1 Mock Test - 9 - JEE MCQ

# KEAM Paper 1 Mock Test - 9 - JEE MCQ

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## 120 Questions MCQ Test KEAM Mock Test Series 2024 - KEAM Paper 1 Mock Test - 9

KEAM Paper 1 Mock Test - 9 for JEE 2024 is part of KEAM Mock Test Series 2024 preparation. The KEAM Paper 1 Mock Test - 9 questions and answers have been prepared according to the JEE exam syllabus.The KEAM Paper 1 Mock Test - 9 MCQs are made for JEE 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for KEAM Paper 1 Mock Test - 9 below.
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KEAM Paper 1 Mock Test - 9 - Question 1

### A d.c. motor having an armature of resistance 2 Ω is designed to operate at 220 V mains. At full speed, it develops a back e.m.f. of 210 V. When the motor is running at full speed, the current in the armature is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 1

When motor is running at full speed the electric current is given by:

KEAM Paper 1 Mock Test - 9 - Question 2

### A solenoid has an inductance of 60 henrys and a resistance of 30 ohms. If it is connected to a 100 volt battery, how long will it take for the current to reach e-1/e=63.2% of its final value

KEAM Paper 1 Mock Test - 9 - Question 3

### A dipole of dipole moment p̅ is placed in uniform electric field E̅, then torque acting on it is given by

KEAM Paper 1 Mock Test - 9 - Question 4

What fraction of a radioactive material will get disintegrated in a period of two half-lives

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 4
KEAM Paper 1 Mock Test - 9 - Question 5

The angular speed of an engine wheel making 90 revolutions per minute is

KEAM Paper 1 Mock Test - 9 - Question 6

What percentage of original radioactive atoms is left after five half lives ?

KEAM Paper 1 Mock Test - 9 - Question 7

An electric dipole is placed along the X-axis at the origin O. A point P is at a distance of 20 cm from this origin such that OP makes an angle π/3 with the X axis. If electric field at P makes an angle θ with X-axis, the value of θ is

KEAM Paper 1 Mock Test - 9 - Question 8

Photons of energy 5.5eV fall on the surface of the metal emitting photoelectrons of maximum kinetic energy 4.0eV. The stopping potential required for these electrons are :

KEAM Paper 1 Mock Test - 9 - Question 9

A man of mass 60 kg. records his wt. on a weighing machine placed inside a lift. The ratio of wts. of man recorded when lift is ascending up with a uniform speed of 2 m/s to when it is descending down with a uniform speed of 4 m/s will be

KEAM Paper 1 Mock Test - 9 - Question 10

A boat of mass 40 kg is at rest. If a dog of mass 4 kg moves in the boat with a velocity of 10 m/s, then velocity of a boat will be

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 10

According to law of conservation of momentum
(md + mbb = md υd
⇒ 44 υb = 4 x 10
⇒ υb = 1 m/s

KEAM Paper 1 Mock Test - 9 - Question 11

A microammeter has a resistance of 100 Ω and full scale range of 50 μ A. It can be used as a voltmeter or as a higher range ammeter provided a resistance is added to it. Pick the correct range and resistance combination

KEAM Paper 1 Mock Test - 9 - Question 12

Spherical balls of radius R are falling in a viscous fluid of viscosity η with a velocity v. The retarding viscous force acting on the spherical ball is

KEAM Paper 1 Mock Test - 9 - Question 13

The symbolic representation of four logic gates are given below:

The logic symbols for OR, NOT and NAND gates are respectively:

KEAM Paper 1 Mock Test - 9 - Question 14

The size of nucleus of an atom of mass number A is proportional to

KEAM Paper 1 Mock Test - 9 - Question 15

A ball is moving to and fro about the lowest point A of a smooth hemisphrical bowl. If it is able to rise up to a height of 20 cm on either side of A, its speed at A must be (Take = 10 m/s2. mass of the body 5 g)

KEAM Paper 1 Mock Test - 9 - Question 16

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): By the study of positive rays, Thomson discovered the existence of isotopes.
Reason(R): Thomson obtained two parabolas for neon gas whose atomic mass is 20.2 .

KEAM Paper 1 Mock Test - 9 - Question 17

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): When a massive projectile collides with a lighter stationary target then maximum speed of target is twice that of projectile.
Reason(R): It is explained by the momentum and energy conservation.

KEAM Paper 1 Mock Test - 9 - Question 18

Two rings of the same radius and mass are placed such that their centres are at a common point and their planes are perpendicular to each other. The moment of inertia of the system about an axis passing through the centre and perpendicular to the plane of one of the ring is (mass = and radius = r)

KEAM Paper 1 Mock Test - 9 - Question 19

A process in which volume remains constant is called

KEAM Paper 1 Mock Test - 9 - Question 20

Erg-m⁻1 can be the unit of measure for

KEAM Paper 1 Mock Test - 9 - Question 21

To demonstrate the phenomenon of interference we require two sources which emit radiations of

KEAM Paper 1 Mock Test - 9 - Question 22
A train is approaching a platform with a velocity ν. The frequency heard by an observer standing at the station is
KEAM Paper 1 Mock Test - 9 - Question 23
In Young's experiment of double slit, the intensity of central bright band is ---- times the individual intensities of the interfering waves
KEAM Paper 1 Mock Test - 9 - Question 24
Standing stationary waves can be obtained in an air column even if the interfering waves are
KEAM Paper 1 Mock Test - 9 - Question 25

The H α line is the first member of the Balmer series of the hydrogen spectrum and it occurs due to the transition of the electron from the 3rd orbit to the 2ndorbit. If its wave length is λ , the wave length of the last member of the Balmer series will be

KEAM Paper 1 Mock Test - 9 - Question 26

If the charge on a capacitor is increased by 2 coulomb, the energy stored in it increases by 21%. The original charge on the capacitor is

KEAM Paper 1 Mock Test - 9 - Question 27

A particle is moving on a circular path with constant speed, then its acceleration will be

KEAM Paper 1 Mock Test - 9 - Question 28

At what temperature will the resistance of a copper wire be three times its value at 0ºC? (Given Temperature coefficient of resistance for copper = 4x10⁻3ºC⁻1)

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 28
For temp. coeff (a)=4×10^-3,
3R=R(1+(a)t)
2/4×10^-3=t
t=500
KEAM Paper 1 Mock Test - 9 - Question 29

How many electrons must be removed from each of two 5.0-kg copper spheres to make the electric force of repulsion between them equal in magnitude to the gravitational attraction between them?

KEAM Paper 1 Mock Test - 9 - Question 30

There are three voltmeters of the same range but of resistance 10000 Ω, 8000 Ω and 4000 Ω respectively. The best voltmeter among these is the one whose resistance is

KEAM Paper 1 Mock Test - 9 - Question 31

The phase difference between the alternating current and e.m.f. is π/2. Which of the following can not be the constituent of the circuit?

KEAM Paper 1 Mock Test - 9 - Question 32

The frequency for which a 5 μF capacitor has a reactance of 1/1000 ohm is given by

KEAM Paper 1 Mock Test - 9 - Question 33

Neutrino is a particle, which is

KEAM Paper 1 Mock Test - 9 - Question 34

Which of the following is true?

KEAM Paper 1 Mock Test - 9 - Question 35

A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 m/sec. A plump bob is suspended from the roof of the car by a light rigid rod of length 1.00 m. The angle made by the rod with track is

KEAM Paper 1 Mock Test - 9 - Question 36

The approximated wavelength of a photon of energy 2.48eV is

KEAM Paper 1 Mock Test - 9 - Question 37

A point Q lies on the perpendicular bisector of an electrical dipole of dipole moment p. If the distance of Q from the dipole is r (much larger than the size of the dipole), then the electric field at Q is proportional to :

KEAM Paper 1 Mock Test - 9 - Question 38

The electric field at the centroid of an equilateral triangle carrying an equal charge q at each of the vertices is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 38

Horizontal component of electricity will cancel out each other.

Hence, the electric field at the centro-id of triangle will be zero.
Enet​ = 0.

KEAM Paper 1 Mock Test - 9 - Question 39

A lift of mass 1000 kg is moving with an acceleration of 1 m−s⁻2 in upward direction. Tension developed in the string, which is connected to the lift, is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 39
Use T-mg=ma with g=9.8You will get T=m(a+g)T=1000(1+9.8)T=1000(10.8)T=10800
KEAM Paper 1 Mock Test - 9 - Question 40

A machine gun fires a bullet of mass 40 g with a velocity 1200 m−s⁻1. The man holding it can exert a maximum force of 144 N on the gun. How many bullets can he fire per second at the most?

KEAM Paper 1 Mock Test - 9 - Question 41

A long solenoid has n turns per metre and current I ampere is flowing through it. The magnetic field at the ends of solenoid is

KEAM Paper 1 Mock Test - 9 - Question 42

The logic behind 'NOR' gate is that, it gives

KEAM Paper 1 Mock Test - 9 - Question 43

Two pieces of a glass plate, placed one upon the other with a little water in between them, can not be separated easily, because of

KEAM Paper 1 Mock Test - 9 - Question 44

The function of the moderator in a nuclear reactor is

KEAM Paper 1 Mock Test - 9 - Question 45

The sum of two vectors A → and B → is at right angles to their difference. Then

KEAM Paper 1 Mock Test - 9 - Question 46

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A):In a nuclear reactor cadmium acts as a moderator.
Reason(R):The cadium rods are so inserted in the graphite block so that they can be slided in and out as per requirement.

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 46
The role of moderator is to slow down the neutron produced due to nuclear fission reaction occurring in nuclear reactors. The cadmium rod is good neutron absorber so it is used to control the number and not to slow them down for reuse.
KEAM Paper 1 Mock Test - 9 - Question 47

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Energy density in the solenoid is greater at centre than near its ends.
Reason(R): Energy density is defined as

KEAM Paper 1 Mock Test - 9 - Question 48

A solid cylinder of mass M and radius R rolls down an inclined plane without slipping. The speed of its centre of mass when it reaches the bottom is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 48
KEAM Paper 1 Mock Test - 9 - Question 49

There are two lead spheres at the same temperature, the ratio of radii being 1:2 The ratio of head capacities are

KEAM Paper 1 Mock Test - 9 - Question 50

For the constructive interference the path difference between the two interfering waves must be equal to

KEAM Paper 1 Mock Test - 9 - Question 51

The fundamental unit which has the same power in the dimensional formula of surface tension and viscosity is

KEAM Paper 1 Mock Test - 9 - Question 52

If a star is moving towards earth, then the lines are shifted towards

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 52
Its shifts towards blue because of increases in frequency by Doppler Effect in optics.
KEAM Paper 1 Mock Test - 9 - Question 53

A parallel monochromatic beam of light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of slit is

KEAM Paper 1 Mock Test - 9 - Question 54

When a tuning fork of frequency 341 is sounded with another tuning fork, six beats per second are heard. When the second tuning fork is loaded with wax and sounded with the first tuning fork, the number of beats is two per second. The natural frequency of the second tuning fork is

KEAM Paper 1 Mock Test - 9 - Question 55

d/dx [tan-1 cosx/(1 + sin x)] =

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 55

KEAM Paper 1 Mock Test - 9 - Question 56

Singly ionized helium (He+) atom is hydrogen like in the sense that a solitary electron revolves around a positively charged nucleus. If the energy of this electron in its first orbit (n = 1) is -54.4 eV, what will be its energy in the first excited state?

KEAM Paper 1 Mock Test - 9 - Question 57

The charge deposited on 4 μ F capacitor in the circuit is

KEAM Paper 1 Mock Test - 9 - Question 58

The angular velocity of the second needle in watch (in rad/s) is

KEAM Paper 1 Mock Test - 9 - Question 59

We are able to obtain fairly large currents in a conductor because

KEAM Paper 1 Mock Test - 9 - Question 60

A charge +4q is located on the X-axis of a Cartesian coordinate system at x = -2a as shown. Another charge +(q/4) is located on the X-axis at x = a. Where on the Y-axis should a third charge -3q be placed so that the resultant electric field at the origin O has equal positive X and Y components?

KEAM Paper 1 Mock Test - 9 - Question 61

Directions: Questions are based on the following paragraph.

When ammonium vanadate is heated with oxalic add solution, a compound Z is formed. A sample of Z was titrated with KMnO4 solution in hot acidic solution. The resulting liquid was reduced with SO2, the excess SOboiled off, and the liquid again titrated with KMnO4. The ratio of the volumes of KMnO4 used in the two titrations was 5 : 1. KMnO4 oxidises all oxidation state of vanadium to Vanadium (+V) and SO2 reduces vanadium (+V) to vanadium (+IV). Read the above experiment and answer the following questions. If vanadium exists as , reduced species by SO2 would be

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 61

is reduced to +4 oxidation state which is

KEAM Paper 1 Mock Test - 9 - Question 62

In a cubic dosed packed structure of mixed oxides, the lattice is made up of oxide ions, one eighth of tetrahedral/voids are occupied by divalent ions (A2+), while one half of the octahedral voids are occupied by trivalent ions(B3+)What is the formula of the oxide ?

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 62

Let number of oxides = x

Number of octahedral void = x

Number of tetrahedral void = 2x

Number of

Hence, formula of oxide is AB2O4.

KEAM Paper 1 Mock Test - 9 - Question 63

Which of the following sequence of reaction is the best means to furnish the conversion RCH2OH→RCH2NH2

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 63

KEAM Paper 1 Mock Test - 9 - Question 64

The standard heat of combustion of carbon(s), sulphur (s) and carbon disulphide (l) are -393.3, -293.72 and - 1108.76 kJ/mol respectively. The standard heat of formation of carbon disulphide(l) is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 64

on putting various enthalpy of formation in equation III

(reactants) - 1108.76 = [-393.3 + 2(-293.72)] -

=-1108.76 = -393.3 -2 x 293.72 -

KEAM Paper 1 Mock Test - 9 - Question 65

The volume of 0.1 M oxalic acid that can be completely oxidised by 20 mL of 0.025 M KMnO4 solution is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 65

KEAM Paper 1 Mock Test - 9 - Question 66

α-D(+)-glucose and β-D-(+)-glucose are

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 66

Anomers are diastereo isomers of cyclic forms of sugars or similar molecules differing in the configuration at the anomeric carbon (C-1 atom of aldose or the  C-2 atom of a 2-ketose).The cyclic forms of carbohydrates can exist in two forms , α – and β- based on the position of the substituent at the anomeric centre.

KEAM Paper 1 Mock Test - 9 - Question 67

Match List I with List II and select the correct answer using the codes given below the lists:

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 67

Cyanide process is used for the extraction of Au, floatation process uses pine oil as a foaming agent, electrolytic reduction is used in the extraction of Al and zone refining process produces ultra pure Ge.

KEAM Paper 1 Mock Test - 9 - Question 68

Which one of the following is the structure of polyacrylonitrile?

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 68

Polyacrylonitrile has molecular formula (C3H3N)n.

Hence its structure is

KEAM Paper 1 Mock Test - 9 - Question 69

In the hydrocarbon

The state of hybrization of carbons 1,3 and 5 are in the following sequence :

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 69

Among the four (I) and (II) have chirality . so, here, optical isomers are obtained.

KEAM Paper 1 Mock Test - 9 - Question 70

If for  then the value of keq for the reaction  will be

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 70

for reaction

KEAM Paper 1 Mock Test - 9 - Question 71

For the elementary reaction M → N, the rate of disappearance of M increases by factor of 8 upon doubling the concentration of M. The order of the reaction with respect to M is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 71

On doubling cone of [M], Rate becomes 8 times

KEAM Paper 1 Mock Test - 9 - Question 72

Calgon used as a water softener is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 72

KEAM Paper 1 Mock Test - 9 - Question 73

In which of the following case, increase in concentration of ion cause increase in Ecell?

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 73

KEAM Paper 1 Mock Test - 9 - Question 74

Directions: Questions  are based on the following paragraph.

When ammonium vanadate is heated with oxalic add solution, a compound Z is formed. A sample of Z was titrated with KMnO4 solution in hot acidic solution. The resulting liquid was reduced with SO2, the excess SOboiled off, and the liquid again titrated with KMnO4. The ratio of the volumes of KMnOused in the two titrations was 5 : 1. KMnO4 oxidises all oxidation state of vanadium to Vanadium (+V) and SO2 reduces vanadium (+V) to vanadium (+IV). Read the above experiment and answer the following questions.

Q. What is the oxidation state of vanadium in the compound Z?

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 74

vanadate ion   is reduce to Vx (species Z) by

ion in acidic medium. Vis oxidised by

∴  to which in turn isoxidised to

volumes of   used in Eqs (1) , (2) are in ratio , of

∴

KEAM Paper 1 Mock Test - 9 - Question 75

Direction: Question is assertion reason type. These question contains two statements Statement I (Assertion), Statement II (Reason). These question also has four alternative choices, only one of which is correct. You have to select the correct choices from the codes (a), (b), (c) and (d) given below:

Statement I : Detection of chlorine in 2, 4, 6 -trinitrochlorobenzene can be done directly by addition of aq. AgNO3 solution.

Statement II: C-Cl bond is weakened by electron withdrawing - NO2 group

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 75

2,4, 6 - trinitrocholorobenzene.The presence of electron withdrawing group (like -NO2) makes the nucleophilic aromatic substitution easier, as it decreases the strength of C-Cl bond. Thus,gives ppt. of AgCl with aq. AgNo3

KEAM Paper 1 Mock Test - 9 - Question 76

Silver (atomic weight = 108 g mol-1 ) has a density of 10.5 g cm-3. The number of silver atoms on a surface of area 10-12 mcan be expressed in scientific notation as y * 10x . The value of x is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 76

since the number of atom of silver

KEAM Paper 1 Mock Test - 9 - Question 77

Names of some compounds are given. Which one is not correct in IUPAC system?

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 77

Correct IUPAC name is 4-ethyl-3-methyl heptane.

KEAM Paper 1 Mock Test - 9 - Question 78

The structure of isobutyl group in an organic compound is :

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 78

Structure of 1 butene-3yne we know that double bond contains one sigma and one pi-bond while a triple bond contains one sigma and two pi-bonds. So, total number of sigma and pi-bonds.

= (5+1+1) σ + (0+1+2) π i.e 7σ, 3π

1-butene-3yne contains 7 sigma and 3 Pi-bonds

KEAM Paper 1 Mock Test - 9 - Question 79

consider the follwing reaction,

the value of x, y and z in the reaction respectively are

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 79

Given

after balancing the equation, we get

∴ The value of x, y and z in the given equation are 2,5 and 16 respectively

KEAM Paper 1 Mock Test - 9 - Question 80

The correct statement about the following disaccharide is

Detailed Solution for KEAM Paper 1 Mock Test - 9 - Question 80

In the given structures A and B ring A is 6 membered ring containg one oxygen with α – glycosidic linkage, hence it is pyranose where as ring B is 5- membered ring containing one oxygen is furanos with β – glycosidic linkage.

KEAM Paper 1 Mock Test - 9 - Question 81

If 5.08 g of a cupric salt is dissolved in water and excess of KI is added to the solution, and the liberated I2 requires 25 ml of M/5 Na2S2O3, where it gets converted into S4O62-, then find the weight percentage of copper in the salt.