Physics - Nuclei - Quiz-8

$M_{p}$ denotes the mass of a proton and $M_{n}$ that of a neutron. A given nucleus of binding energy B contains Z protons and N neutrons. The mass M(N, Z) of the nucleus is given by: (c is the velocity of light)

0%

$M (N, Z) = {NM}_{n} + {ZM}_{p} - {Bc}^{2}$
0%

$M (N, Z) = {NM}_{n} + {ZM}_{p} + {Bc}^{2}$
0%

$M (N, Z) = {NM}_{n} + {ZM}_{p} - B / c^{2}$
0%

$M (N, Z) = {NM}_{n} + {ZM}_{p} + B / c^{2}$

Complete the reaction
$n + {}_{92}^{235}U \to {}_{56}^{144}{Ba} + . . . + 3 n$

0%

${}_{36}^{89}{Kr}$
0%

${}_{36}^{90}{Kr}$
0%

${}_{36}^{91}{Kr}$
0%

${}_{36}^{92}{Kr}$

1 atomic mass unit is equal to

0%
$\frac{1}{25}$ (mass of $F_{2}$ molecules)
0%
$\frac{1}{14}$ (mass of $N_{2}$ molecules)
0%
$\frac{1}{12}$ (mass of one C-atom)
0%
$\frac{1}{16}$ (mass of $O_{2}$ molecules)

The nucleus ${}_{92}^{234}U$ splits exactly in half in a fission reaction in which two neutrons are released. The resultant nuclei are

0%
${}_{46}^{116}{Pd}$
0%

${}_{45}^{117}{Rh}$
0%

${}_{45}^{116}{Rh}$
0%

${}_{46}^{117}{Pd}$

A nucleus is bombarded with a high speed neutron so that resulting nucleus is a radioactive one. This phenomenon is called

0%

Artificial radioactivity
0%

Fusion
0%

Fission
0%

Radioactivity

Which of the following cannot cause fission in a heavy nucleus

0%

$α$ -particle
0%

Proton
0%

Deutron
0%

Laser rays

If the mass number of an atom is A = 40 and its electron configuration is $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6}$ , the number of neutrons and protons in its nucleus will be

0%

22, 18
0%

18, 22
0%

20, 20
0%

18, 18

Which of the following is most unstable

0%

Electrons
0%

Protons
0%

Neutrons
0%

$α$ -particle

Radioactive substance do not emit

0%

Helium nucleus
0%

Positron
0%

Proton
0%
Electron

During a negative beta decay

0%

An atomic electron is ejected
0%

An electron which is already present within the nucleus is ejected
0%

A neutron in the nucleus decays emitting an electron
0%

A part of the binding energy is converted into electron

Some radioactive nucleus may emit

0%

Only one $α, β$ or $γ$ at a time
0%

All the three $α, β$ and $γ$ one after another
0%

All the three $α, β$ and $γ$ simultaneously
0%

Only $α$ and $β$ simultaneously

Which can pass through 20 cm thickness of the steel

0%
$α$ particles
0%

$β$ particles
0%

$γ$ rays
0%

Ultraviolet rays

The half-life period of radium is 1600 years. Its average life time will be
(a) 3200 years (b) 4800 years
(c) 2319 years (d) 4217 years

0%
1
0%
2
0%
3
0%
4

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

0%

0.3%
0%

1%
0%

31%
0%

3.125%

Beta rays emitted by a radioactive material are

0%
Electromagnetic radiation
0%

The electrons orbiting around the nucleus
0%

Charged particles emitted by nucleus
0%

Neutral particles

Alpha rays emitted from a radioactive substance are

0%
Negatively charged particles
0%

Ionised hydrogen nuclei
0%

Doubly ionised helium atom
0%

Uncharged particles having the mass equal to proton

Half life of ${Bi}^{210}$ is 5 days. If we start with 50,000
atoms of this isotope, the number of atoms left over after 10
days is

0%

5,000
0%

25,000
0%

12,500
0%

20,000

A nucleus of atomic mass A and atomic number Z emits $β$ -particles. The atomic mass and atomic number of the resulting nucleus are

0%

A, Z
0%

A + 1, Z
0%

A, Z + 1
0%

A-4, Z-2

Radioactivity was discovered by

0%

Becquerel
0%

Pierre Curie
0%

Roentgen
0%

Rutherford

The average life T and the decay constant $λ$ of a radioactive nucleus are related as

0%

$Tλ = 1$
0%

$T = \frac{0.693}{λ}$
0%

$\frac{T}{λ} = 1$
0%

$T = \frac{c}{λ}$

If T is the half life of a radioactive material, then the fraction that would remain after a time $\frac{T}{2}$ is

0%
$\frac{1}{2}$
0%

$\frac{3}{4}$
0%
$\frac{1}{\sqrt{2}}$
0%

$\frac{\sqrt{2} - 1}{\sqrt{2}}$

Which of the following is in the increasing order for penetrating power

0%

$α, β, γ$
0%

$β, α, γ$
0%

$γ, α, β$
0%

$γ, β, α$

The half life of a radioactive element which has only $\frac{1}{32}$ of its original mass left after a lapse of 60 days is

0%
12 days
0%

32 days
0%

60 days
0%

64 days

The half-life of ${Bi}^{210}$ is 5 days. What time is taken by (7/8)th part of the sample to decay

0%

3.4 days
0%

10 days
0%

15 days
0%

20 days

Radioactivity is

0%

Irreversible process
0%

Self disintegration process
0%

Spontaneous process
0%

All of the above

Half life of radioactive element depends upon

0%
Amount of element present
0%

Temperature
0%

Pressure
0%

Nature of element

The decay constant of radium is $4.28 \times 10^{- 4}$ per year. Its half life will be

0%

2000 years
0%

1240 years
0%

63 years
0%

1620 years

Atomic mass number of an element thorium is 232 and its atomic number is 90. The end product of this radioactive element is an isotope of lead (atomic mass 208 and atomic number 82). The number of alpha and beta particles emitted is

0%
$α$ =3, $β$ = 3
0%

$α$ = 6, $β$ = 4
0%

$α$ =6, $β$ =0
0%

$α$ =4, $β$ =6

A sample contains 16 gm of a radioactive material, the half life of which is two days. After 32 days, the amount of radioactive material left in the sample is

0%
Less than 1 mg
0%

$\frac{1}{4} gm$
0%

$\frac{1}{2} gm$
0%

1 gm

A radio-isotope has a half- life of 5 years. The fraction of the atoms of this material that would decay in 15 years will be

0%
1/8
0%

2/3
0%

7/8
0%

5/8

0:0:1

Practice Physics Quiz Questions and Answers

0:0:1

Practice Physics Quiz Questions and Answers

Support mcqexams.com by disabling your adblocker.