KEAM Paper 1 Mock Test - 8 - JEE MCQ

# KEAM Paper 1 Mock Test - 8 - JEE MCQ

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## 120 Questions MCQ Test KEAM Mock Test Series 2024 - KEAM Paper 1 Mock Test - 8

KEAM Paper 1 Mock Test - 8 for JEE 2024 is part of KEAM Mock Test Series 2024 preparation. The KEAM Paper 1 Mock Test - 8 questions and answers have been prepared according to the JEE exam syllabus.The KEAM Paper 1 Mock Test - 8 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 - 8 below.
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KEAM Paper 1 Mock Test - 8 - Question 1

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

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 1
Given:C=5uf Xc=1/1000. Xc=1/wc=1/1000 ,, wc=10002πf=1000/5u =200*10^6= F=100/π M Hz
KEAM Paper 1 Mock Test - 8 - Question 2

### If the instantaneous current in a circuit is given by: I = 2cos(ω t + φ)A, then r.m.s. value of the current is

KEAM Paper 1 Mock Test - 8 - Question 3

### When the speed of electrons increases, then the value of its specific charge

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 3
Because these electrons are losing energy.
KEAM Paper 1 Mock Test - 8 - Question 4
To see first 20 lines of Balmer series distinctly, minimum resolving power of instrument should be
KEAM Paper 1 Mock Test - 8 - Question 5

In which of the following systems will the radius of the first orbit (n = 1) be minimum

KEAM Paper 1 Mock Test - 8 - Question 6

A ball weighing 10 g hits a hard surface vertically with a speed of 5 ms⁻1 and rebounds with the same speed. The ball remains in contact with the surface for 0.01 s. The average force exerted by the surface on the ball is

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 6
Since, F=P/T

where, P= change in momentum and T = total time

F= ( mv1 - mv2 )/T

F= { 0.01[5-(-5)]}/0.01

F=10 N
KEAM Paper 1 Mock Test - 8 - Question 7

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

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 7
Torque=p×E.

It is due to the reason that torque is a vector quantity .therefore we use a cross product to measure the torque acting on the body
KEAM Paper 1 Mock Test - 8 - Question 8

In a certain 0.1m3 of space, electric potential is found to be 5V throughout. The electric field in this region is

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 8
Consider there is sphere of volume 0.1m3 now since it is in space it is a hollow sphere so electric field inside it will be zero now this was the easy method u can also do it by taking a sphere and deriving values.
KEAM Paper 1 Mock Test - 8 - Question 9

A ball of mass 0.25 kg attached to the end of a string of length 1.96 m is moving in a horizontal circle. The string will break if the tension is more than 25 N. What is the maximum speed with which the ball can be moved?

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 9

Given,
Length of String, l = 1.96m
Mass of Ball, m = 0.25 Kg
Maximum Tension of String, Tmax = 25 N
Let the speed of the balls is v m/s
In the horizontal circular motion of the ball tension in the string is balanced by the centrifugal force (mv2/l) and hence the maximum tension in the string will be for the maximum speed of the ball (since m and l are fixed)
Therefore,

Therefore, maximum speed of the ball will be 14 m/s

KEAM Paper 1 Mock Test - 8 - Question 10

A ball of mass m strikes elastically a wall at an angle of 30º with velocity ν. The change in momentum is

KEAM Paper 1 Mock Test - 8 - Question 11

A current passing through a circular coil of two produces a magnetic field of 8 T at its centre. The coil is then rewound, so as to have four turns and current is passed through it is doubled. Now magnetic field at the centre of the coil will be

KEAM Paper 1 Mock Test - 8 - Question 12

The following figure shows a logic gate circuit with two inputs A and B and the output C. The voltage waveforms of A, B and C are as shown below.

The logic circuit gate is

KEAM Paper 1 Mock Test - 8 - Question 13

Sixty four spherical rain drops of equal size are falling vertically through air with a terminal velocity 1.5 m-s⁻1 If these drops coalesce to form a big spherical drop, then terminal velocity of big drop is

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 13

There is a general formula for calculating the velocity of big drop which is formed by the number of smaller drops The terminal velocity of bigger drop be v' The terminal velocity of smaller drop be v The total no.of smaller drop is 64(n) v'=v×n^2/3 v'=1.5×(64)^2/3 v'=24m/s

KEAM Paper 1 Mock Test - 8 - Question 14

An aeroplane is flying horizontally with a velocity of 600 km/h and at a height of 1960 m. When it is vertically at a point A on the ground, a bomb is released from it. The bomb strikes the ground at point B. The distance AB is

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 14
First resolve the motion is 2 components 1st horizontal and 2nd vertical .
1st vertical component :-

As there is no velocity in the vertical direction so in Italy velocity there will be zero but the gravitational force is acting in that direction so the accleration in the vertical direction will be g(10)m/s^2
Apply equation of motion here and u will get the time i.e about 19.79sec .
Then we have no acceleration in the horizontal direction so simply
Velocity[horizontal] =distance /time
Hence distance will be 3.3km approx
KEAM Paper 1 Mock Test - 8 - Question 15

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 charges are shared between two bodies, there occurs loss of energy.
Reason(R): In case of sharing of charges, conservation of energy fails.

KEAM Paper 1 Mock Test - 8 - Question 16

Number of particles emitted in the reaction is

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 16
The mass number differs by 4 so 1 Alpha, and atomic number differs by 1 so one electron.
KEAM Paper 1 Mock Test - 8 - 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): For refraction in a plane surface v can be used for the light moving from μ1 to μ2.
Reason(R): for light getting into a medium of index μ2 from μ1.

KEAM Paper 1 Mock Test - 8 - Question 18

The moment of inertia of a uniform disc about an axis passing through its centre and perpendicular to its plane is 1kg - m2. It is rotating with an angular velocity 100 radians/second. Another identical disc is gently placed on it so that their centres coincide. Now these two discs together continue to rotate about the same axis. Then the loss in kinetic energy in kilo joules is

KEAM Paper 1 Mock Test - 8 - Question 19
For a gas, if the ratio of specific heats at constant pressure and volume is γ, then the value of degree of freedom is
KEAM Paper 1 Mock Test - 8 - Question 20
KEAM Paper 1 Mock Test - 8 - Question 21
The penetration of light into the region of geometrical shadow is called
KEAM Paper 1 Mock Test - 8 - Question 22

Huygen's wave theory of light can not explain

KEAM Paper 1 Mock Test - 8 - Question 23
When a star moves away from earth, the spectrum of the star shifts towards higher wavelength side. This is due to
KEAM Paper 1 Mock Test - 8 - Question 24
A metal wire of linear mass density 9.8 g/m is stretched with a tension of 10 kg wt between two rigid supports 1 metre apart. The wire passes at its middle point between the poles of a permanent magnet and it vibrates in resonance when carrying an alternating current of frequency n. The frequency n of alternating source is
Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 24
The wire vibrates because of the magnetic force on it. When the alternating current completes one cycle, the wire completes one oscillation and hence the frequency of oscillation of the wir is the same as the frequency of the alternating current (n). Therefore we have

n = (1/2L)√(T/m) where L is the length of the segment of the wire betweenetween the supports, T is the tension and ‘m’ is the linear density (mass per unit length) of the wire. Substituting for L, T and m we have

n = (1/2)√[(10X9.8)/(9.8X10–3 )] = 50 Hz.
KEAM Paper 1 Mock Test - 8 - Question 25
Which of the following will give maximum ions in solution ?
Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 25
A) has 2 ions :- K+& (I3)- , b) & d) have 3 ions , While FeCl3 has 4 ions :- 1Fe+³ and 3 Cl- So (c) has maximum number of ions
KEAM Paper 1 Mock Test - 8 - Question 26

According to the Bohr model, electrons of quantum number n = 4 in excited hydrogen atoms can undergo transitions to lower energy states in different ways and give rise to photons of discrete frequencies. How many discrete frequencies are possible in this case?

KEAM Paper 1 Mock Test - 8 - Question 27

A parallel plate capacitor with air between the plates has a capacitance of 9 pF. The separation between its plates is 'd' . The space between the plates is now filled with two dielectrics. One of the dielectrics has dielectric constant K1 = 3 and thickness d 3 while the other one has dielectric constant K2 = 6 and thickness. 2d 3 Capacitance of the capacitor is now

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 27

KEAM Paper 1 Mock Test - 8 - Question 28

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

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 28
Angular speed=2π × n =2π×(1.5rps)=3 rad/s
KEAM Paper 1 Mock Test - 8 - Question 29

The resistivity of a wire depends on its

KEAM Paper 1 Mock Test - 8 - Question 30

An electron moves in a circular orbit with a uniform velocity v. It produces a magentic field B at the centre of the circle. The radius of the circle is proportional to

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 30

KEAM Paper 1 Mock Test - 8 - Question 31

Which one of the following is not made of soft iron

KEAM Paper 1 Mock Test - 8 - Question 32

The long wavelength limit of Lyman series is

KEAM Paper 1 Mock Test - 8 - Question 33

Two particles having mass M and m are moving in a circular having radius R and r. If their time periods are same then the radio of angular velocity will be

KEAM Paper 1 Mock Test - 8 - Question 34

If A is the mass no. of an element, then volume of the nucleus of an atom of this element is proportional to

KEAM Paper 1 Mock Test - 8 - Question 35

When X-rays pass through a strong uniform magnetic field, then they

KEAM Paper 1 Mock Test - 8 - Question 36

The r.m.s. value of an a.c. of 50 Hz is 10A. The time taken by a.c. in reaching from zero to maximum value and the peak value of current will be

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 36
KEAM Paper 1 Mock Test - 8 - Question 37

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

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 37

KEAM Paper 1 Mock Test - 8 - Question 38

A ball of wt. 0.1 kg coming with speed 30 m/s strikes with a bat and returns in opposite direction with speed 40 m/s, then impulse is

KEAM Paper 1 Mock Test - 8 - Question 39

Electric field at the centroid of a triangle carrying q charge at each corner is

KEAM Paper 1 Mock Test - 8 - Question 40

A monkey of mass 20 kg is holding a vertical rope. The rope will not break when a mass of 25 kg is suspended from it, but will break if the mass exceeds 25 kg. What is the maximum acceleration, with which the monkey can climb up along the rope? (Take g = 10 m−s⁻2)

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 40
M(g+a)=250N So a=2.5 ms-²
KEAM Paper 1 Mock Test - 8 - Question 41

A galvanometer having a resistance of 8 Ω is shunted by a wire of resistance 2 Ω. If the total current is 1 A, then current passing through the shunt will be

KEAM Paper 1 Mock Test - 8 - Question 42

The logic circuit shown below has the input wave forms 'A' and 'B' as shown. Pick out the correct output wave form.

KEAM Paper 1 Mock Test - 8 - Question 43

A motor boat of mass 300 kg is standing in water. If the area of the bottom surface is 120 m2, then the boat will exert a pressure of (Take g=10 m-s⁻2)

KEAM Paper 1 Mock Test - 8 - Question 44

The function of the moderator in a nuclear reactor is

KEAM Paper 1 Mock Test - 8 - Question 45

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): Speed of light in water is less than the speed in air.
Reason(R): Refractive index of water is greater than one .

KEAM Paper 1 Mock Test - 8 - 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 general magnetic force between two charges is much smaller compared to the electric force .
Reason(R): In general velocity of charges << velocity of light in free space.

KEAM Paper 1 Mock Test - 8 - Question 47

For motion in a plane with constant acceleration, a → , initial velocity v 0 → and final velocity ν → after time t, we have

KEAM Paper 1 Mock Test - 8 - Question 48

The least coefficient of friction for an inclined plane inclined at angle α with horizontal in order that a solid cylinder will roll down it without slipping is

KEAM Paper 1 Mock Test - 8 - Question 49

A measure of the degree of disorder of a system is known as

KEAM Paper 1 Mock Test - 8 - Question 50

In young's double slit experiment, the intensity of central maximum is I. It one slit is closed, the intensity at the same place will become

KEAM Paper 1 Mock Test - 8 - Question 51

The energy density and pressure have

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 51

'Co-efficient of friction' is a physical quantity that has no unit and no dimensions.
Though energy density and pressuire have the same dimensions, they do not share the same units, hence they are different physical quantities.

KEAM Paper 1 Mock Test - 8 - Question 52
In young's double slit experiment, three light, blue, yellow and red are used successively. For which colour, will the fringe width be maximum?
KEAM Paper 1 Mock Test - 8 - Question 53

A wavefront is an imaginary surface where

KEAM Paper 1 Mock Test - 8 - Question 54

A transverse progressive wave is given by the equation y = 2 cos [π (0.5x - 200t)], where x and y are in cm and t in sec. Which of the following statement is true for this wave

KEAM Paper 1 Mock Test - 8 - Question 55

Which one of the following statements is WRONG in the context of X-rays generated from a X-ray tube ?

KEAM Paper 1 Mock Test - 8 - Question 56

A condenser is connected across another charged condenser. The energy in the two condenser will be

KEAM Paper 1 Mock Test - 8 - Question 57

A tachometer is a device to measure

KEAM Paper 1 Mock Test - 8 - Question 58

In an experiment to measure the internal resistance of a cell, by a potentiometer, it is found that the balance point is at a length of 2 m, when the cell is shunted by a 5 Ω resistance and is at a length of 3m when the cell is shunted by a 10 Ω resistance. The internal resistance of the cell is

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 58

KEAM Paper 1 Mock Test - 8 - Question 59

The figure to the right shows an edge-on view of three extremely large, parallel insulating sheets positively charged with uniform and identical surface charge densities. In which of the regions shown is the electric field a maximum?

KEAM Paper 1 Mock Test - 8 - Question 60

Cathode rays enter into a uniform magnetic field perpendicular to the direction of the field. In the magnetic field their path will be

KEAM Paper 1 Mock Test - 8 - Question 61

Which of the following can act as reducing agent

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 61

Stability of metal carbonyl is deduced from EAN rule.
EAN rules states – those complex’s in which effective atomic number is numerically equal to atomic number of noble gas element found in same period in which metal is situated, are most stable.
EAN (effective atomic number) =

A. [Co(CO)4]
EAN = 27 – (–1) + 2 × 4
= 36 (inert gas atomic number)
Since, it already has EAN = 36 so it won’t give up or take in any electron.
B. EAN = 25 – (0) + 2 × 6 = 37
It has EAN = 37 so to attain inert gas electronic configuration it will donate one electron

EAN = 25 – (+1) + 2 × 6 = 36
It will act as reducing agent.
C. [Mn(CO)5]
EAN = 25 – (0) + 2 × 5 = 35
To gain inert gas electronic configuration, it will accept one electron.

It will act as oxidizing agent.
D. [Cr(CO)6]
EAN = 24 – (0) + 2 × 6 = 36
It already has inert gas configuration so it won’t exchange electrons.
Hence option (B) is correct.

KEAM Paper 1 Mock Test - 8 - Question 62

If P,Q,R and S are elements of 3rd period of p–block in modern periodic table and among these one element is metal and rest are non-metal and their order of electronegativity is also given as
P < Q < R < S .Then in which of the following release of H+ is relatively easier.

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 62

In any X – O – H, we take into account electronegative difference between X and O, and O and H. If electronegative difference between X and O is greater than O and H, X – O bond will be more polar and will break easily giving OH. If electronegative difference between O and H is larger than X and O, O – H bond will be more polar and easier to break.
Electronegativity of S is largest, so electronegative difference between S and O will be least in S – O – H. It will be easier to break O – H bond, giving

Hence option (E) is correct.

KEAM Paper 1 Mock Test - 8 - Question 63

In which of the following ‘meta form’ of ‘-ic acid’ is not possible.

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 63

For meta form of an acid to exist it must be capable of giving one H2O molecule and also contain at least one ‘H’ after donation of water.

KEAM Paper 1 Mock Test - 8 - Question 64

Bakelite is a

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 64

Structure of bakelite

KEAM Paper 1 Mock Test - 8 - Question 65

If mechanism of reaction is

Where k is rate constant then, what is

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 65

KEAM Paper 1 Mock Test - 8 - Question 66

which of the following species undergo non–redox thermal decomposition reaction on heating

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 66

Non–redox decomposition implies no change in oxidation number
On taking a look at these options we observe only in option (D) there has been no change in oxidation number.
Hence, option (D) is correct

KEAM Paper 1 Mock Test - 8 - Question 67

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 67

Step 1:: HCN attacks the carbonyl and forms hydrocyanin compound.

Step 2:
LiAlH4 reduces —CN to —CH2—NH2

Step 3:
creates carbocation which then expands and get stabilized.

Hence, option (A) is correct.

KEAM Paper 1 Mock Test - 8 - Question 68

ksp for AgCl is-
Given: T = 25 °C

are 17.7, 13.2 and 23.0 cal/mol. (Antilog 0.21 =1.6)

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 68

KEAM Paper 1 Mock Test - 8 - Question 69

If NaCl is doped with 10–2 mol% of SrCl2, which of the following option shows concentration of cation vacancies?

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 69

Doping of NaCl with 10–2 mol% SrCl2 means that 100 mol of NaCl are doped with 10–2 mol of SrCl2.
100 mol of NaCl doped with = 10–2 mol SrCl2
1 mol of NaCl doped with

Each  ion introduces one cation vacancy,
therefore, cation vacancy: 10–4 mol/mol of NaCl
= 10–4 × 6.023 × 1023 mol–1
= 6.02 × 1019 mol–1 of NaCl
Hence, option B is correct.

KEAM Paper 1 Mock Test - 8 - Question 70

Product A is;

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 70

Mechanism:

Carbocation is formed.

(ii)

Hence option (C) is correct answer.

KEAM Paper 1 Mock Test - 8 - Question 71

0.5 molal solution acetic acid (M.W. = 60) in benzene (M.W. = 78) boils at 80.80 °C. The normal boiling point of benzene is 80.10 °C and Δvap H = 30.775 KJ/mol. Which of the following option is correct regarding percent of association of acetic acid in benzene.

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 71

Given to (boiling point of benzene) = 80.10 °C = 353.1K molality (m) = 0.5
Δvap H = 30.775 KJ/mol
MW1 (benzene) = 78

KEAM Paper 1 Mock Test - 8 - Question 72

Ore of Y would be

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 72

Cinnabar (HgS) is Ore of Hg.
Siderite is FeCO3
Malachite is Cu2CO3(OH)2
Hornsilver is AgCl
Hence, option (E) is correct.

KEAM Paper 1 Mock Test - 8 - Question 73

Product is:

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 73

step 1:

Step 2: Ring expansion to make more stable carbocation.

Step 3:

KEAM Paper 1 Mock Test - 8 - Question 74

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 74

(i) NBS reagent is used for allylic substitution.
(ii) NBS is used for Bromination.

KEAM Paper 1 Mock Test - 8 - Question 75

[X3B ← NH3], in which of the following boric halide, tendency to accept electrons from nitrogen of ammonia will be least (X = halogens)

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 75

In BF3, due to F back bonding to B, least Lewis acid character is observed. So out of above four, BF3 will have least tendency to accept electron from NH3.
Hence, option (D) is correct.

KEAM Paper 1 Mock Test - 8 - Question 76

E1, E2 and E3 are activation energies then, which of the following is correct.

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 76

Here, aromaticity is being ruptured hence activation energy is highest.

Here double bonds are in conjugation, so it will be difficult to hydrogenate then. E2 will also be high but not so high as E1.

Here, no conjugation or aromaticity present in reaction so process will be easy. E3 will be lowest.
E1 > E2 > E3.
Hence, option D is correct.

KEAM Paper 1 Mock Test - 8 - Question 77

The ionic molar conductivities of  ions are x, y and z S cm2 mol–1, respectively then value of  of (NaOOC – COOK) is

Detailed Solution for KEAM Paper 1 Mock Test - 8 - Question 77

According KOOC to Kohlrausch law:

KEAM Paper 1 Mock Test - 8 - Question 78

For a gas obeying the van der waals equation at critical temperature, which of the following is true.