NEET Part Test - 6 - NEET MCQ

# NEET Part Test - 6 - NEET MCQ

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## 180 Questions MCQ Test NEET Mock Test Series 2025 - NEET Part Test - 6

NEET Part Test - 6 for NEET 2024 is part of NEET Mock Test Series 2025 preparation. The NEET Part Test - 6 questions and answers have been prepared according to the NEET exam syllabus.The NEET Part Test - 6 MCQs are made for NEET 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for NEET Part Test - 6 below.
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NEET Part Test - 6 - Question 1

### A radioactive nuclide A decays to nuclide B which further decays to C. Their disintegration constant are λ1 and λ2 respectively. At t = 0 only nuclei A are present. Number of nuclei A at t = 0  is N0.

Detailed Solution for NEET Part Test - 6 - Question 1

Rate of decay of A keeps on decreasing continuously because concentration of A decreases with time ⇒ A is false Initial rate of production of B is λ1N° and rate of decay is zero. With time, as the number of B atoms increase, the rate of its production decreases and its rate of decay increases. Thus the number of nuclei of B will first increase and then decrease B is the correct choice
The initial activity of B is zero whereas initial activity of A is λ1N0 ⇒ C is false.
As time t → ∞ : NA = 0, NB = 0 and NC = N0 ⇒ D is false

NEET Part Test - 6 - Question 2

### An enclosure filled with helium is heated to a temperature of 400 K. Helium atom emerges out of the enclosure. The mean debroglie wavelength of the helium atoms is :

Detailed Solution for NEET Part Test - 6 - Question 2

⇒  ⇒
Substituting values :

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NEET Part Test - 6 - Question 3

### When a metallic surface is illuminated with monochromatic light of wavelength λ, the stopping potential is 5 V0. When the same surface is illuminated with light of wavelength 3λ, the stopping potential is V0. Then the work function of the metallic surface is :

Detailed Solution for NEET Part Test - 6 - Question 3

NEET Part Test - 6 - Question 4

No. of identical photons incident on a perfectly black body of mass m kept at rest on smooth horizontal surface. Then the acceleration of the body if n number of photons incident per second is (Assume wavelength of photon to be λ) :

Detailed Solution for NEET Part Test - 6 - Question 4

Change in momentum due to photon = h/λ
F = rate of change of momentum
⇒

NEET Part Test - 6 - Question 5

If we assume that penetrating power of any radiation/particle is inversely proportional to wavelength of the particle then :

Detailed Solution for NEET Part Test - 6 - Question 5

∴ For higher m and q ;
λ will be smaller.
For an 'α' particle; both 'm' and 'q' are higher hence lesser is the wavelength.
As, (penetrating power) ∝ Energy From above; penetrating power of an α-particle is more than that of a proton.

NEET Part Test - 6 - Question 6

Two radioactive sources A and B initially contain equal number of radioactive atoms. Source A has a half-life of 1 hour and source B has a half-life of 2 hours. At the end of 2 hours, the ratio of activity of source A to that of B is :

Detailed Solution for NEET Part Test - 6 - Question 6

NEET Part Test - 6 - Question 7

The radionuclide 238U decays by emitting an alpha particle.

238U → 234Th + 4He
The atomic masses of the three isotopes are.
238U      238.05079 amu
238U      234.04363 amu
4He       4.00260 amu

What is the maximum kinetic energy of the emitted alpha particle? Express your answer in Joule.

Detailed Solution for NEET Part Test - 6 - Question 7

Mass defect  = (238.05079 - 234.04363 - 4.00260) u = 4.56 x 10-3 u
= 4.56 x 10-3 x 1.66 x 10-27 = 7.57 x 10-30 kg
mc2 = 7.57 x 10-30 x 9 x 1016 = 6.8 x 10-13 .

NEET Part Test - 6 - Question 8

Choose the correct statement.

Detailed Solution for NEET Part Test - 6 - Question 8

The correct statement in nuclear force is not a central force.

NEET Part Test - 6 - Question 9

A beam of electrons striking a copper target produces X-rays.Its spectrum is as shown. Keeping the voltage same if the copper target is replaced with a different metal, the cut-off wavelength and characteristic lines of the new spectrum will change in comparision with old as :

Detailed Solution for NEET Part Test - 6 - Question 9

Cut- off wavelength of emitted X-rays depends on maximum kinetic energy of incident electrons on the target and is independent of nature of target. The characteristic lines depend on nature of material of target.

NEET Part Test - 6 - Question 10

Both the frequency and the intensity of a beam of light falling on the surface of photoelectric material are increased by a factor of two. This will :

Detailed Solution for NEET Part Test - 6 - Question 10

The maximum K.E. of ejected photoelectrons is (K.E)max = hv – φ0
If the frequency of photon is doubled, maximum kinetic energy of photon electrons becomes

Photo current
If intensity and frequency both are doubled. the photocurrent remains same.

NEET Part Test - 6 - Question 11

The photon radiated from hydrogen corresponding to 2nd line of Lyman series is absorbed by a hydrogen like atom ‘X’ in 2nd excited state. As a result the hydrogen like atom ‘X’ makes a transition to nth orbit. Then,

Detailed Solution for NEET Part Test - 6 - Question 11

Energy of nth state in Hydrogen is same as energy of 3nth state in Li++.
∴ 3 → 1 transition in H would give same energy as the 3 x 3 → 1 x 3 transition in Li++

NEET Part Test - 6 - Question 12

The angular momentum of an electron in first orbit of Li++ ion is :

Detailed Solution for NEET Part Test - 6 - Question 12

Angular momentum  (∵ n = 1)

NEET Part Test - 6 - Question 13

An electron of mass ' m ', when accelerated through a potential V has de-Broglie wavelength λ. The de-Broglie wavelength associated with a proton of mass M accelerated through the same potential difference will be:

Detailed Solution for NEET Part Test - 6 - Question 13

⇒
K = qV is same for both proton and electron.

NEET Part Test - 6 - Question 14

Two hydrogen atoms are in excited state with electrons residing in n = 2. First one is moving towards left and emits a photon of energy E1 towards right. Second one is moving towards left with same speed and emits a photon of energy E2 towards left. Taking recoil of nucleus into account during emission process

Detailed Solution for NEET Part Test - 6 - Question 14

In the first case K.E. of H-atom increases due to recoil whereas in the second case K.E. decreases due to recoil.
∴ E2 > E1

NEET Part Test - 6 - Question 15

In a hydrogen atom following the Bohr’s postulates the product of linear momentum and angular momentum is proportional to (n)x where ‘n’ is the orbit number. Then ‘x’ is :

Detailed Solution for NEET Part Test - 6 - Question 15

Linear momentum ⇒
angular momentum ⇒  mr α n
∴ product of linear momentum and angular momentum α n0

NEET Part Test - 6 - Question 16

One of the lines in the emission spectrum of Li2+ has the same wavelength as that of the 2nd line of Balmer series in hydrogen spectrum. The electronic transition corresponding to this line is :

Detailed Solution for NEET Part Test - 6 - Question 16

For 2nd line of Balmer seires in hydrogen specturm

For Li2+ :
which is satisfied by transition n = 12 to n = 6

NEET Part Test - 6 - Question 17

The ratio of wave length of a photon of energy E and deBroglie wavelength of an electron of mass 'm' having the kinetic energy also E is : (Speed of light = c)

Detailed Solution for NEET Part Test - 6 - Question 17

For an electron with kinetic energy E :
and for a photo  :
∴

NEET Part Test - 6 - Question 18

An orbital electron in the ground state of hydrogen has an angular momentum L1 and an orbital electron in the first orbit in the ground state of lithium (double ionised positively charged) has an angular momentum L2 .Then :

Detailed Solution for NEET Part Test - 6 - Question 18

Doubly ionised positively lithium ion is a hydrogen like atom :

which depends only on the value of n. Also for both n = 1.

NEET Part Test - 6 - Question 19

If in the first orbit of a hydrogen atom the total energy of the electron is -21.76 x 10-19J, then its electric potential energy will be :

Detailed Solution for NEET Part Test - 6 - Question 19

Potential energy = 2 Total energy = 2 x – 21.76 x 10-19 = – 43.52 x 10-19

NEET Part Test - 6 - Question 20

In an x - ray tube, if the accelerating potential difference is changed, then:

Detailed Solution for NEET Part Test - 6 - Question 20

As the accelerating potential difference is changed only the minimum wavelength changes.
It has no effect on wavelengths of characteristic x-rays (whether they are produced or not)

NEET Part Test - 6 - Question 21

All electrons ejected from a surface by incident light of wavelength 200 nm can be stopped before travelling 1 m in the direction of uniform electric field of 4 N/C. The work function of the surface is:

Detailed Solution for NEET Part Test - 6 - Question 21

The electron ejected with maximum speed vmax are stopped by electric field E = 4N/C after travelling a distance d = 1m
∴
The energy of incident photon  = 1240/200 = 6.2 eV
From equation of photo electric effect

∴

NEET Part Test - 6 - Question 22

The energy ratio of two Kα  photons obtained in x-ray from two metal targets of atomic numbers Z1 and Z2 is:

Detailed Solution for NEET Part Test - 6 - Question 22

The energy of Kα x-ray photons is directly propotional to (Z-1)2 . The energy ratio of two Kα photons obtained in x-ray from two metal targets of atomic numbers

NEET Part Test - 6 - Question 23

Because of the space charge in a diode valve,

NEET Part Test - 6 - Question 24

A point source of light is used in a photoelectric effect.If the source is removed farther from the emitting metal,the stopping potential

NEET Part Test - 6 - Question 25

The X-ray beam coming from an X-ray tube

NEET Part Test - 6 - Question 26

Cutoff wavelength of X-rays coming from a Coolidge tube depends on the

NEET Part Test - 6 - Question 27

The mass number of a nucleus is

NEET Part Test - 6 - Question 28

The radii of nuclei of two atoms are in ratio 3/2 . Assuming them to be Hydrogen like atom, the ratio of their orbital radius for K shell will be (assume no. of proton = No. of neutron for each atom)

NEET Part Test - 6 - Question 29

A semiconducting device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to almost zero. The device may be

NEET Part Test - 6 - Question 30

A radioactive nucleus ' X ' decays to a stable nucleus ' Y '. Then the graph of rate of formation of ' Y' against time ' t ' will be :

NEET Part Test - 6 - Question 31

The wavelengths of Kα x-rays of two metals 'A and 'B are respectively, where ‘R’ is Rydberg constant. The number of elements lying between 'A' and 'B' according to their atomic numbers is

Detailed Solution for NEET Part Test - 6 - Question 31

⇒ z1 = 26
⇒ z2 = 31
Therefore, 4 elements lie between A and B.

NEET Part Test - 6 - Question 32

A free neutron decays to a proton but a free proton does not decay to a neutron out side nucleus. This is beacuse

Detailed Solution for NEET Part Test - 6 - Question 32

As proton mass is less than neutron mass proton does not decay to neutron outside nucleus.

NEET Part Test - 6 - Question 33

An α particle with a kinetic energy of 2.1 eV makes a head on collision with a hydrogen atom moving towards it with a kinetic energy of 8.4 eV. The collision.

Detailed Solution for NEET Part Test - 6 - Question 33

For completely inelastic collision both come to rest after collision and net energy of 4E + E = 10.5 eV is lost. But electron in ground state of H-atom can accept only an energy of 10.2 eV. Hence the collision may be inelastic but it can never be perfectly inelastic.

NEET Part Test - 6 - Question 34

A monochromatic radiation of wavelength λ is incident on a sample containing He+. As a result the Helium sample starts radiating. A part of this radiation is allowed to pass through a sample of atomic hydrogen gas in ground state. It is noticed that the hydrogen sample has started emitting electrons whose maximum Kinetic Energy is 37.4 eV. (hc = 12400 eV Å) Then λ is -

Detailed Solution for NEET Part Test - 6 - Question 34

Maximum energy of radiation incident on H-sample = KEmax of electron + 13.6 eV = 51eV this energy corresponds to the transition n = 4 → n = 1 in Helium
For electrons of the He to get excited to n = 4

NEET Part Test - 6 - Question 35

The work function of a certain metal is . When a monochromatic light of wavelength λ < λ0  is  incident such that the plate gains a total power P. If the efficiency of photoelectric emission is η% and all the emitted photoelectrons are captured by a hollow conducting sphere of radius R already charged to potential V, then neglecting any interaction between plate and the sphere, expression of potantial of the sphere at time t is :

Detailed Solution for NEET Part Test - 6 - Question 35

Potential of the sphere at any time

NEET Part Test - 6 - Question 36

The Kinetic energy must an ?-particle possess to split a deutron H2 whose binding energy is Eb = 2.2 MeV -

Detailed Solution for NEET Part Test - 6 - Question 36

Loss in K.E. will be used in splitting of Deutron.
Let us calculate the minimum K.E. required for the loss of 2.2 MeV. For this we must assume perfectly inelastic collision.
=
maximum loss of K.E. will be in perfectly inelastic collision. By energy conservation.
⇒

⇒
∴

NEET Part Test - 6 - Question 37

Assuming that about 20 MeV of energy is released per fusion reaction, 1H2 + 1H30n1 + 2He4, the mass of 1H2 consumed per day in a future fusion reactor of power 1 MW would be approximately

Detailed Solution for NEET Part Test - 6 - Question 37

no of moles 1H2 consumed

∴ m = 0.1 g

NEET Part Test - 6 - Question 38

A hydrogen atom is in the 4th excited state, then:

Detailed Solution for NEET Part Test - 6 - Question 38

The hydrogen atom is in n = 5 state.

Max. no of possible photons = 4
To emit photon in ultra violet region, it must jump to n = 1, because only Lyman series lies in u.v. region. Once it jumps to n = 1 photon, it reaches to its ground state and no more photons can be emitted. So only one photon in u. v. range can be emitted.
If H atom emits a photon and then another photon of Balmer series, option D will be correct.

NEET Part Test - 6 - Question 39

In the photoelectric experiment, if we use a monochromatic light, the I - V curve is as shown. If work function of the metal is 2eV, estimate the power of light used. (Assume efficiency of photo emission = 10-3%, i.e. number of photoelectrons emitted are 10-3% of number of photons incident on metal.)

Detailed Solution for NEET Part Test - 6 - Question 39

The energy of incident photons is given by
hv = eVs + φ0 = 2 + 5 = 7 eV (Vs is stopping potential and φ0 is work function)
Saturation current (η is photo emission efficiency)
∴ P = 7W.

NEET Part Test - 6 - Question 40

If first excitation potential of a hydrogen like atom is V volt, then the ionization energy of this atom will be :

Detailed Solution for NEET Part Test - 6 - Question 40

First excitaion energy
∴
∴

NEET Part Test - 6 - Question 41

The element which has kα x-rays line of wavelength 1.8 Å is

Detailed Solution for NEET Part Test - 6 - Question 41

⇒

NEET Part Test - 6 - Question 42

When an impurity is doped into an intrinsic semiconductor,the cunductivity of the semiconductor

NEET Part Test - 6 - Question 43

A radioactive nucleus can decay by either emitting an α particle or by emitting a β particle. Probability of α decay is 75% while that of β decay is 25%. The decayconstant of α decay is λ1 and that of β decay is

Detailed Solution for NEET Part Test - 6 - Question 43

NEET Part Test - 6 - Question 44

Nuclei of radioactive element A are produced at rate t2 ' at any time t. The element A has decay constant λ. Let N be the number of nuclei of element A at any time t. At time is minimum.  Then the number of nuclei of element A at time t = t0 is

Detailed Solution for NEET Part Test - 6 - Question 44

⇒

NEET Part Test - 6 - Question 45

A cobalt (atomic no. = 27) target is bombarded with electrons, and the wavelengths of its characteristic x-ray spectrum are measured. A second weak characteristic spectrum is also found, due to an impurity in the target. The wavelengths of the Kα lines are 225.0 pm (cobalt) and 100.0 pm (impurity). Atomic number of the impurity is (take b = 1)

Detailed Solution for NEET Part Test - 6 - Question 45

Using Mosely's law for both cobalt and impurity
⇒
⇒  and
⇒

NEET Part Test - 6 - Question 46

Match column-I with column-II and select the correct answer using the codess given below :

Detailed Solution for NEET Part Test - 6 - Question 46

(a) Tin-cassiterite, SnO2
(c) Iron-siderite, FeCO3
Therefore, (B) option is correct.

NEET Part Test - 6 - Question 47

Which is not a correct statement ?

Detailed Solution for NEET Part Test - 6 - Question 47

Sulphide ore is roasted in presence of excess of air or O2 below its melting point to convert into the oxide and to remove the impurities of S, P, Sb etc., as their volatile oxides. In some cases roasting of certain sulphide ores provide directly the metals.

NEET Part Test - 6 - Question 48

Which metal is extracted using a hydrometallurgical process involving complexation ?

Detailed Solution for NEET Part Test - 6 - Question 48

4Ag + 8CN- + 2H2O → 4[Ag(CN)2]- (soluble complex) + 4OH-
2[Ag(CN)2]- + Zn → 2Ag + [Zn(CN)4]2- Hydrometallurgy involves the dissolution of ores in suitable chemical reagent followed by precipitation of the metal from their solution by more electropositive metal.

NEET Part Test - 6 - Question 49

Which of  the following acids is monobasic?

Detailed Solution for NEET Part Test - 6 - Question 49

It has one replaceable hydrogen.

NEET Part Test - 6 - Question 50

ClO2 is the anhydride of :

Detailed Solution for NEET Part Test - 6 - Question 50

As it gives mixture of two acids, HCIO2 and HCIO3, it is called as mixed anhydride of HCIO2 and HCIO3.
2ClO2+ H2O → HClO+ HClO3

NEET Part Test - 6 - Question 51

.... is obtained when ammonium dichromate is heated.

Detailed Solution for NEET Part Test - 6 - Question 51

NEET Part Test - 6 - Question 52

In the Ostwald’s process, nitric acid is prepared by the catalytic oxidation of :

Detailed Solution for NEET Part Test - 6 - Question 52

4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g) ; NO + 1/2O2 → NO2
3NO2 + H2O → 2HNO3 + NO.

NEET Part Test - 6 - Question 53

The thermal stability of hydrides of oxygen family is in order :

Detailed Solution for NEET Part Test - 6 - Question 53

Down the group (H — E) bond dissociation enthalpy decreases as (H — E) bond length increases because of increase in size of cation. Thus thermal stability of hydrides also decreases.

NEET Part Test - 6 - Question 54

Which of the following gaseous molecules is monoatomic ?

Detailed Solution for NEET Part Test - 6 - Question 54

Noble gases exist as monoatomic molecules.

NEET Part Test - 6 - Question 55

The transition elements have a general electronic configuration :

Detailed Solution for NEET Part Test - 6 - Question 55

General electronic configuration of transition elements is [Noble gas]

NEET Part Test - 6 - Question 56

The stable oxidation state of Cr is :

Detailed Solution for NEET Part Test - 6 - Question 56

Cr3+ is most stable because in aqueous solution it has higher CFSE on account of half filled t32g energy level of 3d orbitals in octahedral spliting.

NEET Part Test - 6 - Question 57

Which of the following ions gives colourless aqueous solution?

Detailed Solution for NEET Part Test - 6 - Question 57

Cu+ is diamagnetic with 3d10 configuration; so no d-d transition is possible and thus colourless.

NEET Part Test - 6 - Question 58

The developer used in photography is an alkaline solution of :

Detailed Solution for NEET Part Test - 6 - Question 58

NEET Part Test - 6 - Question 59

At 300ºC, FeCl3 :

Detailed Solution for NEET Part Test - 6 - Question 59

NEET Part Test - 6 - Question 60

What is the charge on the complex [Cr(C2O4)2(H2O)2] formed by Cr(III) ?

Detailed Solution for NEET Part Test - 6 - Question 60

Chromium has + 3 charge. H2O is neutral ligand while C2O42- is negative ligand. Charge on the complex is algebric sum of the charges on metal ion and ligands present in the coordination sphere.
So, the charge on the complex will be 3 + 2(-2) = - 1

NEET Part Test - 6 - Question 61

The correct IUPAC name for the compound [Co(NH3)4CI(ONO)]Cl is :

Detailed Solution for NEET Part Test - 6 - Question 61

Cation is named first followed by anion. In coordination sphere the ligands are named alphabetically followed by name of metal ion and then its oxidation state in Romman numeral. In [Co(NH3)4Cl(ONO)]+CI-, cobalt is in +3 oxidation state and the complex is cationic. ONO ligand attach to metal ion through O atom ; so — O — is used while naming as nitrito before the name of metal ion. So IUPAC name given in option (D) is correct.

NEET Part Test - 6 - Question 62

EAN of a metal carbonyl M(CO)x is 36. If atomic number of metal M is 26, what is the value of x ?

Detailed Solution for NEET Part Test - 6 - Question 62

Let x = number of lone pairs of electrons donated to central metal ion.
EAN = number of electrons in metal ion + number of lone pairs of electrons donated by the ligands.
Therefore, 26 + 2x = 36 or x = 10/2 = 5

NEET Part Test - 6 - Question 63

Which one of the following complexes produces three moles of silver chloride when its one mole is treated with excess of silver nitrate ?

Detailed Solution for NEET Part Test - 6 - Question 63

As 3 mole of CI- are present out side the coordination spehre i.e. in ionisation sphere so according to the following reaction, 3CI-+ 3Ag+ → 3AgCI, one mole of complex will give three moles of AgCI precipitate.

NEET Part Test - 6 - Question 64

Which statement is incorrect ?

Detailed Solution for NEET Part Test - 6 - Question 64

CO is stronger field ligand, so it compels for pairing of electrons.

So, it is tetrahedral but not paramagnetic as all electrons are paired.

NEET Part Test - 6 - Question 65

Which has maximum paramagnetic nature ?

Detailed Solution for NEET Part Test - 6 - Question 65

[Mn(H2O)6]2+ contains maximum number of unpaired electrons i.e. five. so it has maximum paramagnetic character.

NEET Part Test - 6 - Question 66

Which one of the following complexes has highest stability ?

Detailed Solution for NEET Part Test - 6 - Question 66

It is a chelate complex having three five-membered rings. It attains extra stability through chelation.

NEET Part Test - 6 - Question 67

[Co(NH3)5NO2]Cl2 and [Co(NH3)5ONO]Cl2 are related to each other as :

Detailed Solution for NEET Part Test - 6 - Question 67

NO2- is an ambidentate ligand and thus it can linkage to metal ion through O as well as through N. Hence it shows linkage isomerism.

NEET Part Test - 6 - Question 68

When a mixture of solid NaCl, solid K2Cr2O7 is heated with concentrated H2SO4, deep red vapours are obtained. This is due to the formation of :

Detailed Solution for NEET Part Test - 6 - Question 68

NEET Part Test - 6 - Question 69

Precipitate of PbSO4 is soluble in :

Detailed Solution for NEET Part Test - 6 - Question 69

PbSO4 + 2CH3COONH4 → (NH4)2SO4 + (CH3COO)2Pb.

NEET Part Test - 6 - Question 70

Nitrate is confirmed by ring test. The brown colour of the ring is due to formation of :

Detailed Solution for NEET Part Test - 6 - Question 70

2NO3- + 4H2SO4 + 6Fe2+ → 6Fe3+ + 2NO + 4SO42-+ 4H2O.
Fe2+ + NO + SO42- → [Fe(NO)]2+SO42-

NEET Part Test - 6 - Question 71

Nessler’s reagent is :