12583 + Mcqs in Physics Page 240 McqOptions

11951.	A nucleus \[_{n}{{X}^{m}}\]emits one \[\alpha \] and one \[\beta \] particles. The resulting nucleus is [CBSE PMT 1998; BHU 2001; AFMC 2002]
A.	\[_{n}{{X}^{m-4}}\]
B.	\[_{n-2}{{Y}^{m-4}}\]
C.	\[_{n-4}{{Z}^{m-4}}\]
D.	\[_{n-1}{{Z}^{m-4}}\]
Answer» E.

Discussion

11952.	In the uranium radioactive series, the initial nucleus is \[_{92}{{U}^{238}}\]and the final nucleus is \[_{82}P{{b}^{206}}\]. When the uranium nucleus decays to lead, the number of \[\alpha -\]particles emitted will be [MP PMT 1999]
A.	1
B.	2
C.	4
D.	8
Answer» E.

Discussion

11953.	The radioactive decay of uranium into thorium is expressed by the equation\[_{92}^{238}U\to _{90}^{234}Th+X,\]where \['X'\]is [MP PMT 1996, 2002; AMU (Engg.) 2000]
A.	An electron
B.	A proton
C.	A deuteron
D.	An alpha particle
Answer» E.

Discussion

11954.	After two hours, one- sixteenth of the starting amount of a certain radioactive isotope remained undecayed. The half-life of the isotope is [Bihar MEE 1995; Manipal MEE 1995; EAMCET 1994 MP PMT 1997; DPMT 2002; AFMC 2000, 05]
A.	15 minutes
B.	30 minutes
C.	45 minutes
D.	1 hour
Answer» C. 45 minutes

Discussion

11955.	Some radioactive nucleus may emit [IIT 1986]
A.	Only one \[-13.6\ eV\] or \[\gamma \]at a time
B.	All the three \[_{92}{{U}^{238}}\] and \[\gamma \] one after another
C.	All the three \[\alpha ,\ \beta \] and \[\gamma \] simultaneously
D.	Only\[\alpha \] and \[\beta \] simultaneously
Answer» B. All the three \[_{92}{{U}^{238}}\] and \[\gamma \] one after another

Discussion

11956.	A radioactive reaction is\[_{92}{{U}^{238}}{{\to }_{82}}P{{b}^{206}}\]. How many \[\alpha \]and \[\beta \]particles are emitted [BHU 1995; CET 1998; RPET 1996; BHU 2000; AMU (Engg.) 2000]
A.	\[10\alpha ,\ 6\beta \]
B.	4 protons, 8 neutrons
C.	6 electrons, 8 protons
D.	\[6\beta ,\ 8\alpha \]
Answer» E.

Discussion

11957.	16 gm sample of a radioactive element is taken from Bombay to Delhi in 2 hour and it was found that 1 gm of the element remained (undisintegrated). Half life of the element is [MP PMT 1994]
A.	2 hour
B.	1 hour
C.	\[\frac{1}{2}hour\]
D.	\[\frac{1}{4}hour\]
Answer» D. \[\frac{1}{4}hour\]

Discussion

11958.	An archaeologist analyses the wood in a prehistoric structure and finds that \[{{C}^{14}}\](Half-life = 5700 years) to \[{{C}^{12}}\]is only one- fourth of that found in the cells buried plants. The age of the wood is about [NCERT 1982]
A.	5700 years
B.	2850 years
C.	11,400 years
D.	22,800 years
Answer» D. 22,800 years

Discussion

11959.	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 [NCERT 1984; MP PMT 1996; MP PET 1997]
A.	1/8
B.	2/3
C.	7/8
D.	5/8
Answer» D. 5/8

Discussion

11960.	The half-life of \[B{{i}^{210}}\]is 5 days. What time is taken by (7/8)th part of the sample to decay [MNR 1986; Pb. PMT 2001]
A.	3.4 days
B.	10 days
C.	15 days
D.	20 days
Answer» D. 20 days

Discussion

11961.	Consider two nuclei of the same radioactive nuclide. One of the nuclei was created in a supernova explosion 5 billion years ago. The other was created in a nuclear reactor 5 minutes ago. The probability of decay during the next time is [KCET 2005]
A.	Different for each nuclei
B.	Nuclei created in explosion decays first
C.	Nuclei created in the reactor decays first
D.	Independent of the time of creation
Answer» E.

Discussion

11962.	In a sample of radioactive material, what fraction of the initial number of active nuclei will remain undisintegrated after half of a half-life of the sample [Kerala PMT 2005]
A.	\[\frac{1}{4}\]
B.	\[\frac{1}{2\sqrt{2}}\]
C.	\[\frac{1}{\sqrt{2}}\]
D.	\[2\sqrt{2}\]
Answer» D. \[2\sqrt{2}\]

Discussion

11963.	Mean life of a radioactive sample is 100 seconds. Then its half-life (in minutes) is [KCET 2005]
A.	0.693
B.	1
C.	10-4
D.	1.155
Answer» E.

Discussion

11964.	The particle that possesses half integral spin as [EAMCET 2005]
A.	Photon
B.	Pion
C.	Proton
D.	K-meson
Answer» D. K-meson

Discussion

11965.	A nucleus decays by \[{{\beta }^{+}}\] emission followed by a gamma emission. If the atomic and mass numbers of the parent nucleus are Z and A respectively, the corresponding numbers for the daughter nucleus are respectively. [UPSEAT 2005]
A.	\[Z-1\] and \[A-1\]
B.	\[Z+1\] and \[A\]
C.	\[Z-1\] and \[A\]
D.	\[Z+1\] and \[A-1\]
Answer» D. \[Z+1\] and \[A-1\]

Discussion

11966.	A radioactive material has a half-life of 8 years. The activity of the material will decrease to about 1/8 of its original value in [UPSEAT 2005]
A.	256 year
B.	128 year
C.	64 year
D.	24 year
Answer» E.

Discussion

11967.	The half-life of a radioactive substance is 3.6 days. How much of 20 mg of this radioactive substance will remain after 36 days [Pb. PMT 2003]
A.	0.0019 mg
B.	1.019 mg
C.	1.109 mg
D.	0.019 mg
Answer» E.

Discussion

11968.	Carbon dating is best suited for determining the age of fossils if their age in years is of the order of [AIIMS 2004]
A.	\[{{10}^{3}}\]
B.	\[{{10}^{4}}\]
C.	\[{{10}^{5}}\]
D.	\[{{10}^{6}}\]
Answer» C. \[{{10}^{5}}\]

Discussion

11969.	Which of the following rays are not electromagnetic wave [CBSE PMT 2003]
A.	g-rays
B.	b-rays
C.	Heat rays
D.	X-rays
Answer» C. Heat rays

Discussion

11970.	When \[_{90}T{{h}^{228}}\] transforms to \[_{83}B{{i}^{212}}\], then the number of the emitted a- and b-particles is, respectively [MP PET 2002]
A.	\[8\,\alpha ,\,7\beta \]
B.	\[4\,\alpha ,\,7\beta \]
C.	\[4\,\alpha ,\,4\beta \]
D.	\[4\,\alpha ,\,1\beta \]
Answer» E.

Discussion

11971.	Half-life of a substance is 10 years. In what time, it becomes \[\frac{1}{4}\]th part of the initial amount [AIEEE 2002]
A.	5 years
B.	10 years
C.	20 years
D.	None of these
Answer» D. None of these

Discussion

11972.	If a radioactive substance reduces to \[\frac{1}{16}\] of its original mass in 40 days, what is its half-life [DCE 2001; AIIMS 2003]
A.	10 days
B.	20 days
C.	40 days
D.	None of these
Answer» B. 20 days

Discussion

11973.	Certain radio-active substance reduces to 25% of its value in 16 days. Its half-life is [MP PMT 2001]
A.	32 days
B.	8 days
C.	64 days
D.	28 days
Answer» E.

Discussion

11974.	What fraction of a radioactive material will get disintegrated in a period of two half-lives [MP PET 2000]
A.	Whole
B.	Half
C.	One-fourth
D.	Three-fourth
Answer» E.

Discussion

11975.	Complete the equation for the following fission process \[_{92}{{U}^{235}}{{+}_{0}}{{n}^{1}}{{\to }_{38}}S{{r}^{90}}+....\] [CBSE PMT 1998]
A.	\[_{54}X{{e}^{143}}+3{{\ }_{0}}{{n}^{1}}\]
B.	\[_{54}X{{e}^{145}}\]
C.	\[_{57}X{{e}^{142}}\]
D.	\[_{54}X{{e}^{142}}{{+}_{0}}{{n}^{{}}}\]
Answer» B. \[_{54}X{{e}^{145}}\]

Discussion

11976.	A reaction between a proton and \[_{8}{{O}^{18}}\]that produces \[_{9}{{F}^{18}}\]must also liberate [Roorkee 1995]
A.	\[_{0}{{n}^{1}}\]
B.	\[_{1}{{e}^{0}}\]
C.	\[_{1}{{n}^{0}}\]
D.	\[_{0}{{e}^{1}}\]
Answer» B. \[_{1}{{e}^{0}}\]

Discussion

11977.	The mass equivalent of 931 MeV energy is [MP PET 1994; MH CET 2003]
A.	\[1.66\times {{10}^{-27}}kg\]
B.	\[6.02\times {{10}^{-24}}kg\]
C.	\[1.66\times {{10}^{-20}}kg\]
D.	\[6.02\times {{10}^{-27}}kg\]
Answer» B. \[6.02\times {{10}^{-24}}kg\]

Discussion

11978.	What was the fissionable material used in bomb dropped at Nagasaki (Japan) in the year 1945? [MNR 1985; UPSEAT 2003]
A.	Uranium
B.	Nepturium
C.	Berkalium
D.	Plutonium
Answer» E.

Discussion

11979.	During the nuclear fusion reaction [IIT 1987]
A.	A heavy nucleus breaks into two fragments by itself
B.	A light nucleus bombarded by thermal neutrons breaks up
C.	A heavy nucleus bombarded by thermal neutrons breaks up
D.	Two light nuclei combine to give a heavier nucleus and possibly other products
Answer» E.

Discussion

11980.	\[{{M}_{n}}\] and \[{{M}_{p}}\] represent mass of neutron and proton respectively. If an element having atomic mass M has N-neutron and Z-proton, then the correct relation will be [CBSE PMT 2001]
A.	\[M<[N{{M}_{n}}+Z{{M}_{P}}]\]
B.	\[M>[N{{M}_{n}}+Z{{M}_{P}}]\]
C.	\[M=[N{{M}_{n}}+Z{{M}_{P}}]\]
D.	\[M=N[{{M}_{n}}+{{M}_{P}}]\]
Answer» B. \[M>[N{{M}_{n}}+Z{{M}_{P}}]\]

Discussion

11981.	Which of the following isotopes is normally fissionable? [MP PET 1993]
A.	\[_{92}{{U}^{238}}\]
B.	\[_{93}N{{p}^{239}}\]
C.	\[\frac{9}{5}\]
D.	\[\frac{{{n}^{2}}}{Z}\]
Answer» D. \[\frac{{{n}^{2}}}{Z}\]

Discussion

11982.	The binding energy per nucleon is maximum in the case of [CBSE PMT 1993; JIPMER 2001, 02]
A.	\[_{4}^{2}He\]
B.	\[_{26}^{56}Fe\]
C.	\[_{56}^{141}Ba\]
D.	\[_{92}^{235}U\]
Answer» C. \[_{56}^{141}Ba\]

Discussion

11983.	Nucleus of an atom whose atomic mass is 24 consists of [CPMT 1999]
A.	11 electrons, 11 protons and 13 neutrons
B.	11 electrons, 13 protons and 11 neutrons
C.	11 protons and 13 neutrons
D.	11 protons and 13 electrons
Answer» D. 11 protons and 13 electrons

Discussion

11984.	The rest energy of an electron is [MP PMT 1996; BCECE 2003]
A.	510 KeV
B.	931 KeV
C.	510 MeV
D.	931 MeV
Answer» B. 931 KeV

Discussion

11985.	The particles which can be added to the nucleus of an atom without changing its chemical properties are called [NCERT 1979]
A.	Electrons
B.	Protons
C.	Neutrons
D.	None of the above
Answer» D. None of the above

Discussion

11986.	Which of the following cannot cause fission in a heavy nucleus [RPET 2002]
A.	a-particle
B.	Proton
C.	Deutron
D.	Laser rays
Answer» E.

Discussion

11987.	\[{{M}_{p}}\] 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) [CBSE PMT 2004]
A.	\[M(N,\,Z)=N{{M}_{n}}+Z{{M}_{p}}-B{{c}^{2}}\]
B.	\[M(N,\,Z)=N{{M}_{n}}+Z{{M}_{p}}+B{{c}^{2}}\]
C.	\[M(N,\,Z)=N{{M}_{n}}+Z{{M}_{p}}-B/{{c}^{2}}\]
D.	\[M(N,\,Z)=N{{M}_{n}}+Z{{M}_{p}}+B/{{c}^{2}}\]
Answer» D. \[M(N,\,Z)=N{{M}_{n}}+Z{{M}_{p}}+B/{{c}^{2}}\]

Discussion

11988.	Nuclear fusion is common to the pair [CPMT 2004]
A.	Thermonuclear reactor, uranium based nuclear reactor
B.	Energy production in sun, uranium based nuclear reactor
C.	Energy production in sun, hydrogen bomb
D.	Disintegration of heavy nuclei, hydrogen bomb
Answer» D. Disintegration of heavy nuclei, hydrogen bomb

Discussion

11989.	The average binding energy per nucleon in the nucleus of an atom is approximately [EAMCET 1988; CBSE PMT 1992; CPMT 1999; RPET 2002]
A.	8 eV
B.	8 KeV
C.	8 MeV
D.	8 J
Answer» D. 8 J

Discussion

11990.	Work of moderator is [AFMC 2003]
A.	To control the velocity of neutrons
B.	Cooling
C.	As fuel
D.	It is used for safety
Answer» B. Cooling

Discussion

11991.	In the following reaction the value of ?X? is \[_{7}{{N}^{14}}{{+}_{2}}H{{e}^{4}}\,\to \,X{{+}_{1}}{{H}^{1}}\] [DPMT 1999; CPMT 2003]
A.	\[_{8}{{N}^{17}}\]
B.	\[_{8}{{O}^{17}}\]
C.	\[_{7}{{O}^{16}}\]
D.	\[_{7}{{N}^{16}}\]
Answer» C. \[_{7}{{O}^{16}}\]

Discussion

11992.	In an atomic bomb, the energy is released due to [AIIMS 2001]
A.	Chain reaction of neutrons and \[_{92}{{U}^{235}}\]
B.	Chain reaction of neutrons and \[_{92}{{U}^{238}}\]
C.	Chain reaction of neutrons and \[_{92}{{P}^{240}}\]
D.	Chain reaction of neutrons and \[_{92}{{U}^{236}}\]
Answer» B. Chain reaction of neutrons and \[_{92}{{U}^{238}}\]

Discussion

11993.	In nuclear fission the percentage of mass converted into energy is about [KCET 2002]
A.	0.1
B.	0.0001
C.	0.001
D.	0.01
Answer» D. 0.01

Discussion

11994.	Which of the following is true for a sample of isotope containing \[{{U}^{235}}\] and \[{{U}^{238}}\] [RPET 2000]
A.	Number of neutron are same in both
B.	Number of proton, electron and neutron are same in both
C.	Contain same number of protons and electrons but U238 contains 3 more neutrons than U235
D.	U238 contains 3 less neutron then U235
Answer» D. U238 contains 3 less neutron then U235

Discussion

11995.	Hydrogen bomb is based on which of the following phenomenon [CPMT 2000]
A.	Nuclear fission
B.	Nuclear fusion
C.	Radioactive decay
D.	None of these
Answer» C. Radioactive decay

Discussion

11996.	In a nuclear reaction, which of the following is conserved [BHU 1997]
A.	Atomic number
B.	Mass number
C.	Atomic number, mass number and energy
D.	None of these
Answer» D. None of these

Discussion

11997.	For effective nuclear forces, the distance should be [Orissa PMT 2004]
A.	\[{{10}^{-10}}m\]
B.	\[{{10}^{-13}}m\]
C.	\[{{10}^{-15}}m\]
D.	\[{{10}^{-20}}m\]
Answer» D. \[{{10}^{-20}}m\]

Discussion

11998.	In an experiment for positive ray analysis with Thomson method, two identical parabola are obtained when applied electric fields are 3000 and 2000 V/m. The particles are singly ionised particles assuming same magnetic field:
A.	0.04375
B.	0.0861111111111111
C.	0.125694444444444
D.	0.168055555555556
Answer» B. 0.0861111111111111

Discussion

11999.	The rate of disintegration was observed to be 1017 disintegrations per sec when its half-life period is 1445 years. The original number of particles are
A.	\[8.9\times {{10}^{27}}\]
B.	\[6.6\times {{10}^{27}}\]
C.	\[1.4\times {{10}^{16}}\]
D.	\[1.2\times {{10}^{17}}\]
Answer» C. \[1.4\times {{10}^{16}}\]

Discussion

12000.	The binding energy of deuteron \[\begin{matrix} 2 \\ 1 \\ \end{matrix}H\] is 1.112 Me V pen nucleon and an \[\alpha \]-particle \[\begin{matrix} 4 \\ 2 \\ \end{matrix}He\] has a binding energy of 7.047 Me V per nucleon. Then in the fusion reaction \[\begin{matrix} 2 \\ 1 \\ \end{matrix}He+\begin{matrix} 2 \\ 1 \\ \end{matrix}H\to \begin{matrix} 4 \\ 2 \\ \end{matrix}He+Q\], the energy Q released is
A.	\[1\,MeV\]
B.	\[11.9\,MeV\]
C.	\[23.8\,MeV\]
D.	\[931\,MeV\]
Answer» D. \[931\,MeV\]

Discussion

Explore topic-wise MCQs in Joint Entrance Exam - Main (JEE Main).

A nucleus \[_{n}{{X}^{m}}\]emits one \[\alpha \] and one \[\beta \] particles. The resulting nucleus is [CBSE PMT 1998; BHU 2001; AFMC 2002]

In the uranium radioactive series, the initial nucleus is \[_{92}{{U}^{238}}\]and the final nucleus is \[_{82}P{{b}^{206}}\]. When the uranium nucleus decays to lead, the number of \[\alpha -\]particles emitted will be [MP PMT 1999]

The radioactive decay of uranium into thorium is expressed by the equation\[_{92}^{238}U\to _{90}^{234}Th+X,\]where \['X'\]is [MP PMT 1996, 2002; AMU (Engg.) 2000]

After two hours, one- sixteenth of the starting amount of a certain radioactive isotope remained undecayed. The half-life of the isotope is [Bihar MEE 1995; Manipal MEE 1995; EAMCET 1994 MP PMT 1997; DPMT 2002; AFMC 2000, 05]

Some radioactive nucleus may emit [IIT 1986]

A radioactive reaction is\[_{92}{{U}^{238}}{{\to }_{82}}P{{b}^{206}}\]. How many \[\alpha \]and \[\beta \]particles are emitted [BHU 1995; CET 1998; RPET 1996; BHU 2000; AMU (Engg.) 2000]

16 gm sample of a radioactive element is taken from Bombay to Delhi in 2 hour and it was found that 1 gm of the element remained (undisintegrated). Half life of the element is [MP PMT 1994]

An archaeologist analyses the wood in a prehistoric structure and finds that \[{{C}^{14}}\](Half-life = 5700 years) to \[{{C}^{12}}\]is only one- fourth of that found in the cells buried plants. The age of the wood is about [NCERT 1982]

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 [NCERT 1984; MP PMT 1996; MP PET 1997]

The half-life of \[B{{i}^{210}}\]is 5 days. What time is taken by (7/8)th part of the sample to decay [MNR 1986; Pb. PMT 2001]

Consider two nuclei of the same radioactive nuclide. One of the nuclei was created in a supernova explosion 5 billion years ago. The other was created in a nuclear reactor 5 minutes ago. The probability of decay during the next time is [KCET 2005]

In a sample of radioactive material, what fraction of the initial number of active nuclei will remain undisintegrated after half of a half-life of the sample [Kerala PMT 2005]

Mean life of a radioactive sample is 100 seconds. Then its half-life (in minutes) is [KCET 2005]

The particle that possesses half integral spin as [EAMCET 2005]

A nucleus decays by \[{{\beta }^{+}}\] emission followed by a gamma emission. If the atomic and mass numbers of the parent nucleus are Z and A respectively, the corresponding numbers for the daughter nucleus are respectively. [UPSEAT 2005]

A radioactive material has a half-life of 8 years. The activity of the material will decrease to about 1/8 of its original value in [UPSEAT 2005]

The half-life of a radioactive substance is 3.6 days. How much of 20 mg of this radioactive substance will remain after 36 days [Pb. PMT 2003]

Carbon dating is best suited for determining the age of fossils if their age in years is of the order of [AIIMS 2004]

Which of the following rays are not electromagnetic wave [CBSE PMT 2003]

When \[_{90}T{{h}^{228}}\] transforms to \[_{83}B{{i}^{212}}\], then the number of the emitted a- and b-particles is, respectively [MP PET 2002]

Half-life of a substance is 10 years. In what time, it becomes \[\frac{1}{4}\]th part of the initial amount [AIEEE 2002]

If a radioactive substance reduces to \[\frac{1}{16}\] of its original mass in 40 days, what is its half-life [DCE 2001; AIIMS 2003]

Certain radio-active substance reduces to 25% of its value in 16 days. Its half-life is [MP PMT 2001]

What fraction of a radioactive material will get disintegrated in a period of two half-lives [MP PET 2000]

Complete the equation for the following fission process \[_{92}{{U}^{235}}{{+}_{0}}{{n}^{1}}{{\to }_{38}}S{{r}^{90}}+....\] [CBSE PMT 1998]

A reaction between a proton and \[_{8}{{O}^{18}}\]that produces \[_{9}{{F}^{18}}\]must also liberate [Roorkee 1995]

The mass equivalent of 931 MeV energy is [MP PET 1994; MH CET 2003]

What was the fissionable material used in bomb dropped at Nagasaki (Japan) in the year 1945? [MNR 1985; UPSEAT 2003]

During the nuclear fusion reaction [IIT 1987]

\[{{M}_{n}}\] and \[{{M}_{p}}\] represent mass of neutron and proton respectively. If an element having atomic mass M has N-neutron and Z-proton, then the correct relation will be [CBSE PMT 2001]

Which of the following isotopes is normally fissionable? [MP PET 1993]

The binding energy per nucleon is maximum in the case of [CBSE PMT 1993; JIPMER 2001, 02]

Nucleus of an atom whose atomic mass is 24 consists of [CPMT 1999]

The rest energy of an electron is [MP PMT 1996; BCECE 2003]

The particles which can be added to the nucleus of an atom without changing its chemical properties are called [NCERT 1979]

Which of the following cannot cause fission in a heavy nucleus [RPET 2002]

\[{{M}_{p}}\] 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) [CBSE PMT 2004]

Nuclear fusion is common to the pair [CPMT 2004]

The average binding energy per nucleon in the nucleus of an atom is approximately [EAMCET 1988; CBSE PMT 1992; CPMT 1999; RPET 2002]

Work of moderator is [AFMC 2003]

In the following reaction the value of ?X? is \[_{7}{{N}^{14}}{{+}_{2}}H{{e}^{4}}\,\to \,X{{+}_{1}}{{H}^{1}}\] [DPMT 1999; CPMT 2003]

In an atomic bomb, the energy is released due to [AIIMS 2001]

In nuclear fission the percentage of mass converted into energy is about [KCET 2002]

Which of the following is true for a sample of isotope containing \[{{U}^{235}}\] and \[{{U}^{238}}\] [RPET 2000]

Hydrogen bomb is based on which of the following phenomenon [CPMT 2000]

In a nuclear reaction, which of the following is conserved [BHU 1997]

For effective nuclear forces, the distance should be [Orissa PMT 2004]

In an experiment for positive ray analysis with Thomson method, two identical parabola are obtained when applied electric fields are 3000 and 2000 V/m. The particles are singly ionised particles assuming same magnetic field:

The rate of disintegration was observed to be 1017 disintegrations per sec when its half-life period is 1445 years. The original number of particles are