Q.1.
) Electron cannot be constituent of the nucleus because [ AFMC 2010]
-
57%
a) the electron is a negatively charged particle
-
16%
b) the compton wave length of electron is larger than the size of nucleus
-
21%
c) the mass of the electron is very small as compared to the mass of the neutron or proton
-
7%
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}
-
22%
a)-- 52.4 eV
-
32%
b)- 27.2 eV
-
15%
c)- 68 eV
-
31%
d)- 3.4 eV
Explanation
Q.3.
) What is the de- Broglie wave length of 1 kg mass moving with velocity of 10 m/ s ?{AFMC 2001}
-
31%
a) 6.626 × 10 -35 m
-
28%
b) 6.626 × 10 -33 m
-
31%
c) 6.626 × 10 -34 m
-
10%
d) none of these
Explanation
Q.4.
) Which of the following phenomenon shows the transverse nature of light ?{AFMC 2001}
-
48%
a) Photo eletric effect
-
14%
b) Interference
-
26%
c)Polarization
-
12%
d)Difraction
Q.5.
0) The larger scale destruction, that would be caused due to use of nuclear weapons is known as{AFMC 2004}
-
34%
a) neutron holocaust
-
38%
b) thermonuclear reaction
-
22%
c)neutron reproduction factor
-
6%
d)none of these
Q.6.
1) According to classical theory of Rutherford model, the path of electron will be{AFMC 2003}
-
22%
a) parabolic
-
16%
b) hyperbolic
-
40%
c)circular
-
22%
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?
-
22%
a) 6.8 eV
-
41%
b) 3.4 eV
-
23%
c)-3.4 eV
-
13%
d) -6.8 eV
Explanation
Q.8.
The velocity of an electron in the inner most orbit of an atom is ...[ AFMC 1997]
-
48%
a)highest
-
28%
b) lowest
-
9%
c)mean
-
16%
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]
-
34%
a) 2
-
30%
b) 4
-
24%
c)√8
-
13%
d)8
Q.10.
Energy produced in sun is due to ... [ AFMC 1998]
-
27%
a) motion of electrons and ion
-
20%
b) chemical reaction
-
38%
c)fusion reaction
-
14%
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
-
24%
a) 0.0019 mg
-
30%
b) 1.109 mg
-
23%
c) 1.019 mg
-
23%
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]
-
16%
a)neutron reproduction factor
-
59%
b) nuclear holocaust
-
19%
c)thermo nuclear reaction
-
5%
d)none of these
Q.13.
The thermions are
-
31%
a) positron
-
30%
b) photons
-
30%
c)electrons
-
9%
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]
-
21%
a)3.125×109
-
33%
b)3.125×1012
-
37%
c)3.125×1013
-
9%
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]
-
37%
a) 30 min
-
20%
b) 90 min
-
20%
c) 45 min
-
23%
d) 60 min
Explanation
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]
-
26%
a)3860 year
-
28%
b) 4240 year
-
22%
c)2380 year
-
24%
d)1080 year
Explanation
Q.17.
In fission of U235, the percentage of mass converted into energy is about..[ AFMC 2003]
-
33%
a) 0.1%
-
37%
b) 0.25%
-
19%
c)0.3%
-
11%
d)2%
Explanation
Q.18.
A radio active element 90X238 decay into 83X222, then the number of β particle emitted are... [ AFMC 2001]
-
34%
a) 1
-
30%
b) 2
-
24%
c)4
-
12%
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
-
26%
a) 10 kg
-
30%
b) 100kg
-
36%
c) 1 g
-
9%
d) 10-2g
Explanation
Q.20.
The spectrum obtained from a sodium vapour lamp is an example of... [ CBSE-PMT 1995]
-
16%
a)band spectrum
-
23%
b) continuous spectrum
-
44%
c)emission pectrum
-
17%
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]
-
18%
a) 1.9 eV
-
38%
b) 11.1eV
-
30%
c)13.6eV
-
14%
d)0.65eV
Q.22.
The Bohr model of atoms ... [ CBSE-PMT 2004]
-
17%
a) Predicts the same emission spectra for all types of atoms
-
53%
b) assumes that the angular momentum of electrons is quantised
-
19%
c)uses Einstein's photoelectric equation
-
11%
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]
-
62%
a) 3.4 eV
-
22%
b) 6.8eV
-
12%
c) -3.4eV
-
4%
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]
-
44%
a)3200 years
-
21%
b) 4800 years
-
21%
c)6400 years
-
14%
d)2400 years
Q.25.
When hydrogen atom is in its first excited level its radius is .. [ CBSE-PMT 1997]
-
47%
a) four times its ground state radius
-
23%
b) twice
-
23%
c)same
-
8%
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]
-
48%
a) 4a0
-
17%
b) 8a0
-
21%
c)√2 ×a0
-
15%
d)2a0
Q.27.
When electron jump from the fourth orbit to the second orbit, one gets the ... [ CBSE-PMT 2000]
-
28%
b) second line of Paaschen series
-
23%
a) second oline of Lyman series
-
40%
c) second line of Balmar series
-
8%
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?
-
30%
a) 10.2 eV
-
20%
b) 81.6 eV
-
30%
c)20.4 eV
-
20%
d) 40.8 eV
Explanation
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]
-
15%
a)3
-
29%
b) 4
-
32%
c)1
-
25%
d)2
Explanation
Q.30.
Which of the following transitions in hydrogen atoms emits the photon of highest frequency? [ CBSE-PMT 2000]
-
35%
a) n=2 to n=1
-
26%
b) n=2 to n=6
-
21%
c)n=6 to n=2
-
17%
d)n=1 to n=2
Explanation
