Q.1
) The ionigation Potential of hydrogen atom is 13.6 eV. An electron in the ground state absords Photon of energy 12.75 eV. How many dirrerent spectral lines can one expect when electron make a down ward transition
  • a) 1
  • b)2
  • c)6
  • d)4
Q.2
) A radio-active nucleus A Z X emits 3α -particles and 2 Positrions. the ratio of number of neuleuons to that of Protons in the final nucleus will be
  • a)( A - Z - 8 ) / Z - 4
  • b) ( A + Z - 12 ) / Z - 4
  • c) (A - Z - 4 ) / Z - 8
  • d) ( A - Z - 4 ) / Z - 2
Q.3
) An α-particle of energy ½ mv2 bombards by a heavy nuclear target of charge .Thenthe distance of closest approach for the alpha nucleus will be Proportional to
  • a)1/Z3
  • b) 1/ v⁴
  • c)1 / m
  • d)1 / v²
Q.4
6) when 73 Li nucler are bombarded by Proton and the resultant nuclei are 84 Be, then emitted particle will be
  • a) neutron
  • b) gamma
  • c) alpha
  • d)Beta
Q.5
) starting with a sample of Puer cu-66, 7/8 of its decays into Zn in 15 min. The corresponding half-life is
  • a)5 min
  • b)7.5 min
  • c)10 min
  • d) 15 min
Q.6
) An α -particle of energy 5 MeV is scattered though 180 by a fixed uranium nucleus. The distance of the closest approach nucleus The distance of the closest approach is of the order of
  • a) 10-8 cm
  • b) 10-12 cm
  • c) 10-10 cm
  • d) 10-15 cm
Q.7
The binding energy Per nucleon of deutron (2 1H) and Lielium nucleus (4 2He ) 1.1 MeV and 7.0 MeV.respectively. If two beutron nucler react to form a singlehelium nucleus, the energy released is
  • a) 23.6 MeV
  • b) 26.9 MeV
  • c)13.9 MeV
  • d)19.2 MeV
Q.8
) The nucleus at rest disintegrate into two nuclear parts which have their velocities in the ratio 2:1 The ratio of their nuclar sizes will be
  • a) 3√2 :1
  • b) 1 : 3 √2
  • c) 3 : 1
  • d)1 : 3
Q.9
) A radiation of energy E falls normally on a Pertect reflecting surface. The momentum transferred to the surtace is.
  • a) E / c
  • b) 2E / c
  • d)Ec
  • c)E / c²
Q.10
) If the binding energy Per nucleon in 73 Li and 42 He nucler is 5.6 MeV and 7.06 MeV respectively, then in the reaction (P here retrent Proton)energy of Protpn must be
ch-19_que_no-133_img_no1.png
  • a) 1.46 MeV
  • b) 39.2 MeV
  • c) 17.28 MeV
  • d)17.28 MeV
Q.11
) In gamma ray emission form a nucleus
  • a) there is no change in the proton-number and neutron number
  • b) Both the number are changes
  • c)only Proton number change
  • d)only neutron number change
Q.12
) The half life time of a radidactive elements of x is the same as the mean life of another radioactive element Y. Initially they have same number of atoms, then
  • a) y will decay faster than x
  • b) x will decay faster than y
  • c) x and y will decay at the same rate at all time
  • d)x and y will decay at the same rate intially
Q.13
) which of the following transition in hydrogen atoms emits Photon of highest frequengy?
  • a) n=2 to n=6
  • b) n=1 to n=2
  • c) n=2 to n=1
  • d) n=6 to n=2
Q.14
) The binding energy per nucleon for the Parent nucleus is E1 and that for the daughter nuclei is E 2 then
  • a) E 1 < E 2
  • b) E 1 > E 2
  • c) E 1=E 2
  • d) E 1=2 E 2
Q.15
) A and B are two radioactive substane whose half lives are 1 and 2 years respectively. Initially 10 g of A and 1 g of B is taken. The time after which they will have same quantity remaining is
  • a) 3.6 years
  • b) 7 years
  • c)6.6 years
  • d)5 years
Q.16
) which of these is a fusion reuction
  • a) 31H + 21H=42 + 10n
  • b) 127C → 126 C + β + + γ
  • c) 23892 → 29882 Pb + 8( 42He) + 6( 10e)
  • d) none of these
Q.17
) The activity of a sample of a radio- active material is at time t1 and A2 at time t 2 (where t2 > t1) if T its mean life is then
  • a)A1t1 A2t2
    ch-19_qn-145choice_img_no2.png
  • b)
  • c)A₂ - A₁=t₂ - t₁
  • d)A₂=A₁ e(t₂ / t₁)T
Q.18
6) The energy released by the fission of one unanium atom is 200 MeV. The number of fission Per second required to Produce 3.2 w of Power is
  • a) 1010
  • b) 107
  • c) 1012
  • d) 1011
Q.19
) In the following disintegration series 92 U 238 → α→ X → -β → z Y A The value of Z and A respectively will be
  • a)90 , 234
  • b) 92 , 236
  • c)88 , 234
  • d)91 , 234
Q.20
) If 92 U 238 undergoes sucesively 8α decays and 6β decays then resulting nucleus is
  • a) Pb 206
  • b) Pb 208
  • c) Pb 214
  • d) None of these
Q.21
) Radio carbon dating is done by estimating in the specimen
  • a)the amount of oridinary carbon still present
  • b) the radio of the amounts of 14 C 6 + 12 C 6
  • c) the amount of radio carbon still Present
  • d) none of these
Q.22
) The wave length of second line of Balmer series is 486.4 nm. what is the wave length of the first line of lyman saries ?
  • a) 364.8 nm
  • b) 729.6 nm
  • c) 121.6 nm
  • d) None of these
Q.23
) The innermost orbit of the hydrogen atom has a radius 0.53 Å. what is radius of 2nd orbit is ?
  • a) 2.12 Å
  • b) 1.06 Å
  • c) 21.2 Å
  • d) 10.6 Å
Q.24
) If a hydrogen atom emits a Photon of wave length, the recoil speed of the atom of mass m is given by
  • a) h / mλ
  • b) mh / λ
  • c)mhλ
  • d)mλ/h
Q.25
) A freshly Prepared radio active source of half time 2 hr emits raditation of intenisity which is 64 times the Permissible safe level. The minimum time after which is would be possible to work safely with this source is.
  • a)6 h
  • b) 24 h
  • c)12 h
  • d)36 h
Q.26
) In Rutherford experiment, the numer of Particles sccttered at 900 angle are 28 Per min. then the number of Particles at the angle 1200 in Per min will be
  • a) 25
  • b) 12.0
  • c) 50
  • d) 112
Q.27
) The Rutherford revolution per second made by an electron in the first Bohr orbit of hydrogen atom is of the order of
  • a)1015
  • b) 1020
  • c)1010
  • d)1019
Q.28
) The half time of a radioactive substance is 20 min, difference between points of time when it is 33% disintegeated and 67% dissintenated is approximately
  • a) 10 min
  • b) 20 min
  • c)40 min
  • d)30 min
Q.29
) The size of the atom is of the order of
  • a) 10-14 m
  • b) 10-10 m
  • c) 10-8 m
  • d) 10-6 m
Q.30
) The size of the nucleus is of the order of
  • a) 10-10 m
  • b) 10-14 m
  • c) 10-19 m
  • d) 10-3 m
0 h : 0 m : 1 s