Q.1
) Electron cannot be constituent of the nucleus because [ AFMC 2010]
  • a) the electron is a negatively charged particle
  • b) the compton wave length of electron is larger than the size of nucleus
  • c) the mass of the electron is very small as compared to the mass of the neutron or proton
  • d) None of these
Q.2
7) The energy of the ground electronic state of hydrogen atom is - 13.6 eV. The energy of the first excited state will be{AFMC 2001}
  • a)-- 52.4 eV
  • b)- 27.2 eV
  • c)- 68 eV
  • d)- 3.4 eV
Q.3
) What is the de- Broglie wave length of 1 kg mass moving with velocity of 10 m/ s ?{AFMC 2001}
  • a) 6.626 × 10 -35 m
  • b) 6.626 × 10 -33 m
  • c) 6.626 × 10 -34 m
  • d) none of these
Q.4
) Which of the following phenomenon shows the transverse nature of light ?{AFMC 2001}
  • a) Photo eletric effect
  • b) Interference
  • c)Polarization
  • d)Difraction
Q.5
0) The larger scale destruction, that would be caused due to use of nuclear weapons is known as{AFMC 2004}
  • a) neutron holocaust
  • b) thermonuclear reaction
  • c)neutron reproduction factor
  • d)none of these
Q.6
1) According to classical theory of Rutherford model, the path of electron will be{AFMC 2003}
  • a) parabolic
  • b) hyperbolic
  • c)circular
  • d)elliptical
Q.7
) The total energy of the elcton in the first excited state of hydrogen is -3.4 eV. what is the kinatic energy of the electron in this state?
  • a) 6.8 eV
  • b) 3.4 eV
  • c)-3.4 eV
  • d) -6.8 eV
Q.8
The velocity of an electron in the inner most orbit of an atom is ...[ AFMC 1997]
  • a)highest
  • b) lowest
  • c)mean
  • d)zero
Q.9
The mass number of He is 4 and that of sulphur isThe radius of sulphur nucleus is larger than that of helium by a factor of ...[ AFMC 1997]
  • a) 2
  • b) 4
  • c)√8
  • d)8
Q.10
Energy produced in sun is due to ... [ AFMC 1998]
  • a) motion of electrons and ion
  • b) chemical reaction
  • c)fusion reaction
  • d)fission reaction
Q.11
The half life of a radio active substance is 3.6 days. How much of 20 mg of that radioactive substance will remain after 36 days
  • a) 0.0019 mg
  • b) 1.109 mg
  • c) 1.019 mg
  • d) 0.019 mg
Q.12
The large scale destruction, that would be caused due to the use of nuclear weapons is known as.. [ AFMC 1999]
  • a)neutron reproduction factor
  • b) nuclear holocaust
  • c)thermo nuclear reaction
  • d)none of these
Q.13
The thermions are
  • a) positron
  • b) photons
  • c)electrons
  • d)protons
Q.14
The energy released by fission of one atom of 92U235 is 200 MeV. The number of fission required per second to produce a power of 1kW is ..[ AFMC 2001]
  • a)3.125×109
  • b)3.125×1012
  • c)3.125×1013
  • d)3.125×1011
Q.15
A substance reduces to one sixteenth of its original mass in 2 hours. The half life period of the substance will be..[ AFMC 2000]
  • a) 30 min
  • b) 90 min
  • c) 45 min
  • d) 60 min
Q.16
A radio active material decays by simultaneous emission of two particles with respective half life-lives of 1620 year and 810 year. The time, after which one fourth of the materiel remains, is...[ AFMC 2002]
  • a)3860 year
  • b) 4240 year
  • c)2380 year
  • d)1080 year
Q.17
In fission of U235, the percentage of mass converted into energy is about..[ AFMC 2003]
  • a) 0.1%
  • b) 0.25%
  • c)0.3%
  • d)2%
Q.18
A radio active element 90X238 decay into 83X222, then the number of β particle emitted are... [ AFMC 2001]
  • a) 1
  • b) 2
  • c)4
  • d)6
Q.19
Assuming that about 200 MeV energy is released per fission of 92U235 nuclei. What would be the mass of U-235 consumed per day in the fission reactor of power 1MW approximately
  • a) 10 kg
  • b) 100kg
  • c) 1 g
  • d) 10-2g
Q.20
The spectrum obtained from a sodium vapour lamp is an example of... [ CBSE-PMT 1995]
  • a)band spectrum
  • b) continuous spectrum
  • c)emission pectrum
  • d)absorption spectrum
Q.21
Out of the following which is not a possible energy for photon to be emitted by hydrogen atom according to Bohr's atomic model? [ CBSE-PMT 2011]
  • a) 1.9 eV
  • b) 11.1eV
  • c)13.6eV
  • d)0.65eV
Q.22
The Bohr model of atoms ... [ CBSE-PMT 2004]
  • a) Predicts the same emission spectra for all types of atoms
  • b) assumes that the angular momentum of electrons is quantised
  • c)uses Einstein's photoelectric equation
  • d)predicts continuous emission spetra for atoms
Q.23
The total energy of an electron in the first excited state of hydrogen atom is about -3.4eV. Its kinetic energy in this state is .. [ CBSE-PMT 2005]
  • a) 3.4 eV
  • b) 6.8eV
  • c) -3.4eV
  • d) -6.8eV
Q.24
The half life of radium is about 1600 years. If 100 g of radiumm exists now, 25g will remain unchanged after... [ CBSE-PMT 2004]
  • a)3200 years
  • b) 4800 years
  • c)6400 years
  • d)2400 years
Q.25
When hydrogen atom is in its first excited level its radius is .. [ CBSE-PMT 1997]
  • a) four times its ground state radius
  • b) twice
  • c)same
  • d)half
Q.26
In terms of Bohr's radius a0, the radius of the second Bohr orbit of Hydrogen atom is given by... [ CBSE-PMT 1992]
  • a) 4a0
  • b) 8a0
  • c)√2 ×a0
  • d)2a0
Q.27
When electron jump from the fourth orbit to the second orbit, one gets the ... [ CBSE-PMT 2000]
  • b) second line of Paaschen series
  • a) second oline of Lyman series
  • c) second line of Balmar series
  • d) first line of Pfund series
Q.28
) The enery difference between the first two levels of hydrogen atom is 10.2 eV. what is the corresponding energy difference for a singly ionized helium atom?
  • a) 10.2 eV
  • b) 81.6 eV
  • c)20.4 eV
  • d) 40.8 eV
Q.29
The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion. The atomic number of Z of hydrogen like ion is .. [ CBSE-PMT 2011]
  • a)3
  • b) 4
  • c)1
  • d)2
Q.30
Which of the following transitions in hydrogen atoms emits the photon of highest frequency? [ CBSE-PMT 2000]
  • a) n=2 to n=1
  • b) n=2 to n=6
  • c)n=6 to n=2
  • d)n=1 to n=2
0 h : 0 m : 1 s