Nuclei Test

Result

Nuclei Test - 34

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

The mass defect in a particular nuclear reaction in 0.3 grams.The amount of energy liberated in kilowatt hour is $$\left( Velocity\ of \ light=3\times { 10 }^{ 8 }m/s \right) $$

A
$$1.5\times { 10 }^{ 6 }$$

B
$$2.5\times { 10 }^{ 6 }$$

C
$$3\times { 10 }^{ 6 }$$

D
$$7.5\times { 10 }^{ 6 }$$

Solution

Mass defect in a nuclear reaction $$\Delta M = 0.3 g = 3 \times 10^{-4} kg$$
Thus amount of energy released $$E = \Delta M c^2 = (3 \times 10^{-4}) \times (3 \times 10^8)^2 J$$
$$\implies E = 27 \times 10^{12} J (1 kWh = 3.6 \times 10^6 J)$$
$$\therefore E = 7.5 \times 10^{6} kWh $$
Question 2
1 / -0

In an $$\alpha$$-decay the kinetic energy of $$\alpha$$-particle is $$48 \ MeV$$ and $$Q$$-value of the reaction is $$50\ MeV$$. The mass number of the molecular nucleus is $$X$$. Find value of $${ X }/{ 25 }$$.
(Assume that daughter nucleus is in ground state.)

A
$$2$$

B
$$4$$

C
$$6$$

D
$$8$$

Solution

We have: $${ K }_{ a }=\displaystyle \frac { { m }_{ y } }{ { m }_{ y }+{ m }_{ \alpha } } Q$$

$$\Rightarrow { K }_{ \alpha }=\displaystyle \frac { A-4 }{ A } Q$$

$$\Rightarrow 48=\dfrac { A-4 }{ A } \times 50$$

$$\Rightarrow A=100$$
Question 3
1 / -0

When the number of nucleons in nuclei increases, the binding energy per nucleon

A
increases continuously with mass number

B
decreases continuously with mass number

C
remains constant with mass number

D
first increases and then decreases with increase of mass number

Solution

From curve we can see first binding energy increases with number of nucleons in nucleus and later start decreasing.
Question 4
1 / -0

The masses of neutron and proton are $$1.0087 a.m.u.$$ and $$1.0073 a.m.u. $$ respectively. If the neutrons and protons combine to form a helium nucleus (alpha particles) of mass $$4.0015 a.m.u$$, then the binding energy fo the helium nucleus will be: ($$1\ a.m.u. = 931 MeV$$)

A
$$28.4\ MeV$$

B
$$20.8\ MeV$$

C
$$27.3\ MeV$$

D
$$14.2\ MeV$$

Solution

$$B.E.=\Delta m{ c }^{ 2 }$$
$$=\Delta \times 931\ MeV\\ =\left[ 2\left( 1.0087+1.0073 \right) -4.0015 \right] \times 931\\ =28.4\ MeV$$
Question 5
1 / -0

If the total binding energies of $$_{ 1 }^{ 2 }H$$, $$_{ 2 }^{ 4 }He$$, $$_{ 26 }^{ 56 }{ Fe }$$ & $$_{ 92 }^{ 235 }{ U }$$ are $$2.22, 28.3, 492$$ and $$1786 MeV$$ respectively, identify the most stable nucleus of the following

A
$$_{ 26 }^{ 56 }{ Fe }$$

B
$$_{ 1 }^{ 2 }H$$

C
$$_{ 92 }^{ 235 }{ U }$$

D
$$_{ 4 }^{ 2 }He$$

Solution

$$B.{ E }_{ H }=\dfrac { 2.22 }{ 2 } =1.11$$

$$B.{ E }_{ He }=\dfrac { 28.3 }{ 2 } =7.08$$

$$B.{ E }_{ Fe }=\dfrac { 492 }{ 56 } =8.78=$$ maximum

$$B.{ E }_{ U}=\dfrac { 1786 }{ 235 } =7.6$$

$$_{ 26 }^{ 56 }{ Fe }$$ is most stable as it has maximum binding energy per nucleon.
Question 6
1 / -0

If mass-energy equivalence is taken into account, when water is cooled to form ice, the mass of water should

A
increase

B
remain unchanged

C
decrease

D
first increase then decrease

Solution

Because thermal energy decreases, therefore mass should increase.
Question 7
1 / -0

In the process of fission, the binding energy per nucleon

A
increases

B
decreases

C
remains unchanged

D
increases for mass number $$A<56$$ nuclei but decreases for mass number $$A>56$$ nuclei

Solution

For fission, energy to be realeased
$$ E = (BE)_{products} - (BE)_{reactants}$$
If products have to be more stable than the reactant, the BE per nucleon has to be higher for products.
Hence, it releases the energy and reaction continues.
Question 8
1 / -0

Statement-I : Energy is released when heavy nuclei undergo fission or light nuclei undergo fusion and
Statement-11: For heavy nuclei, binding energy per nucleon increases with increasing Z. while for light nuclei it decreases with increasing Z.

A
Both the statements are true and Statement 2 is the correct explanation for Statement 1.

B
Both the statements are true but Statement 2 is not the correct explanation for Statement 1.

C
Statement 1 is true but Statement 2 is false.

D
Statement 1 is false but Statement 2 is true.

Solution

Statement-I: Both, heavy nuclei and light nuclei have low value of binding energy per nucleon. Heavy nuclei splits (fission) into light nuclei and light nuclei combine (fusion) to attain the stability i.e. higher value of binding energy per nucleon. In both processes, some mass is disappeared which is converted into energy i.e. release of energy . (statement is TRUE) .
Statement-II: For heavy nuclei the binding energy decreases with increasing Z and for light nuclei binding energy per nucleon increases with increasing Z.
Question 9
1 / -0

Consider the nuclear change
$$^{237}_{93}X\, \xrightarrow{- \alpha}\, A\, \xrightarrow{- \beta}\, B\xrightarrow{- \alpha}\,C$$
Which of the following statements is not correct?

A
Mass number of B is 233

B
Atomic number of A is 91

C
C is an isotope of A

D
B is an isobar of A

Solution

$$_{93}X^{237} \xrightarrow{-\alpha} _{91}A^{233}\xrightarrow{-\beta} _{92}B^{233} \xrightarrow{-\alpha} _{90}C^{229}$$
(Isotopes have same atomic number but different mass number)
Question 10
1 / -0

The mass of a $$^7_3Li$$ nucleus is $$0.042 u$$ less than the sum of the masses of all its nucleons. What is the binding energy per nucleon of $$^7_3Li$$ nucleus ?

A
$$23 MeV$$

B
$$46 MeV$$

C
$$5.6 MeV$$

D
$$3.9 MeV$$

Solution

As, $$1u\equiv 931\ MeV$$
So, Binding energy of $${}_3^7Li$$ is $$0.042\times931=39.102\ MeV$$
Binding energy per nucleon is $$39.102/7=5.59\approx5.6\ MeV$$

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Nuclei Test - 34

Result

Nuclei Test - 34

Score

-

Rank

-

SHARING IS CARING

Question 1

$$1.5\times { 10 }^{ 6 }$$

$$2.5\times { 10 }^{ 6 }$$

$$3\times { 10 }^{ 6 }$$

$$7.5\times { 10 }^{ 6 }$$

Solution

Question 2

$$2$$

$$4$$

$$6$$

$$8$$

Solution

Question 3

increases continuously with mass number

decreases continuously with mass number

remains constant with mass number

first increases and then decreases with increase of mass number

Solution

Question 4

$$28.4\ MeV$$

$$20.8\ MeV$$

$$27.3\ MeV$$

$$14.2\ MeV$$

Solution

Question 5

$$_{ 26 }^{ 56 }{ Fe }$$

$$_{ 1 }^{ 2 }H$$

$$_{ 92 }^{ 235 }{ U }$$

$$_{ 4 }^{ 2 }He$$

Solution

Question 6

increase

remain unchanged

decrease

first increase then decrease

Solution

Question 7

increases

decreases

remains unchanged

increases for mass number $$A<56$$ nuclei but decreases for mass number $$A>56$$ nuclei

Solution

Question 8

Both the statements are true and Statement 2 is the correct explanation for Statement 1.

Both the statements are true but Statement 2 is not the correct explanation for Statement 1.

Statement 1 is true but Statement 2 is false.

Statement 1 is false but Statement 2 is true.

Solution

Question 9

Mass number of B is 233

Atomic number of A is 91

C is an isotope of A

B is an isobar of A

Solution

Question 10

$$23 MeV$$

$$46 MeV$$

$$5.6 MeV$$

$$3.9 MeV$$

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.